![Sera Nitrite-Test (NO2)-15ml[Volume - 15ml]](https://cdn.shopify.com/s/files/1/0888/7091/2273/files/5BSR04410_5D_20Sera_20Nitrite-Test_20_28NO2_29-15ml_5BVolume_20-_2015ml_5D.png?v=1780606380)
Shipping Estimate
USA
- USA
- CAN
- USA
- CAN
Ships within 48 hours · Estimated delivery Jul 6 - Jul 11
Promo Codes Available:
For Your Every Summer RSVP, with Code: SUMMER15
Description
Sera Nitrite-Test (NO2)-15ml[Volume - 15ml]This product simplifies the process of checking nitrite levels in both fresh and saltwater environments. Nitrite (NO2) is one of the most harmful substances for fish in aquariums and can accumulate in the water when biological filtration is inadequate. The sera NO2 Test allows for effortless and accurate monitoring of nitrite levels in both fresh and marine waters. We suggest utilizing sera bio nitrivec (for freshwater), sera marin bio reefclear (for
This product simplifies the process of checking nitrite levels in both fresh and saltwater environments. Nitrite (NO2) is one of the most harmful substances for fish in aquariums and can accumulate in the water when biological filtration is inadequate. The sera NO2-Test allows for effortless and accurate monitoring of nitrite levels in both fresh and marine waters. We suggest utilizing sera bio nitrivec (for freshwater), sera marin bio reefclear (for marine water), or sera pond bio nitrivec (for ponds) if nitrite levels are slightly elevated. For more serious nitrite issues, sera Nitrite-minus offers rapid assistance. This test kit is sufficient for approximately 75 measurements.
Instructions for use: Click here
Shipping Notes
- Free Standard Shipping on $100+ Orders to the USA.
- Except Preorder products are shipped in 48 hours.
- Delivery to the USA:
- Standard Shipping : 3-10 business days
- If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
- We offer a 30-day return/exchange service after receiving.
- Final sale items are not eligible for returns or exchanges.
- To process your return/exchange, please contact us at [email protected]
- Please click here for more details>>> Return & Exchange Policy
4.7 ★★★★★
Based on 837 reviews
Sort
Product Reviews
★★★★★ 5
Great Banana Plugs!
Size: 6 Pairs / 12 pcs
These FosPower banana plugs work very well. I have used dozens of these great FosPower banana plugs over the years, and they definitely work as advertised. When comparing apples to apples (or bananas in this case....lol), all Banana plugs work virtually the same way, and these banana plugs are no different. Strip speaker wire, unscrew banana plug cover, loosen speaker wire retaining screw(s), insert speaker wire, tighten speaker wire retaining screw(s), screw on banana plug cover, and wallah, a secure/conductive speaker/amplifier wire connector is created. Albeit, some banana plugs require the speaker wire to be splayed over a hollow post, and then they are held down by a screw-on retainer/cover. However, I much prefer these FosPower dual retaining screw type of banana plugs for their speaker wire holding ability.
I always use high quality 14 gauge OFC speaker wire with these FosPower banana plugs, and they work perfectly together. I have used these FosPower banana plugs with many different speaker and amplifier brands over the years, including Klipsch, Pioneer, Polk, Denon, Dayton Audio, and Fosi with no problems at all. They just work, and work well. I have never had a FosPower banana plug break, release the speaker wire or short out, in all of the years that I have used them.
Yes, these FosPower banana plugs do fit rather tightly into the connectors, at first, on a lot of speaker and amplifier brands/models. However, after the initial "squeeze" the banana plugs will lossen up, and become easier to install and remove. However, they still retain their great holding ability even after the initial squeeze. In order to overcome this initial "tightness," I usually just stick the FosPower banana plugs into a connector of an old portable amplifier, before assembling them, in order to squeeze them before inserting them into their final speaker or amplifier destinations. This is especially useful when working in tight places, where there is not much room to work in order to push the FosPower banana plugs into their tight connections firmly.
Overall, I highly recommend these FosPower banana plugs. I am currently using them all over the house and shop for home theater and music listening (and testing projects). Just be aware of the tight fit in some speakers and amplifiers. Also, the 2 very tiny speaker wire retaining screws can be a challenge sometimes. Just use a good standard blade jewelers screwdriver, and be careful not to remove the retaining screws all of the way or over-tighten them. Once these things are mastered, using these FosPower banana plugs becomes second nature. Have fun!
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on August 28, 2024
★★★★★ 5
Great Product
Size: 6 Pairs / 12 pcs
These banana plugs have worked perfectly, no matter what gauge I have run in them, they work great. Easy assembly and great quality.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 8, 2026
★★★★★ 4
The most legit banana plugs I could find on Amazon
Size: 6 Pairs / 12 pcs, Size: 6 Pairs / 12 pcs
NEW PREFACE:: I am kind of glad I first bought the horribly magnetic, horribly made and GOLD PAINTED Sewell crimp on plugs (some reviewers say that Sewell are better and easier to use than the FosPower, which is true in design, but in quality of materials FosPower beats them hands down!!) ... Changing from those to these FosPower plugs plus the Monoprice 90° plugs, I am flabbergasted at the difference they make in sound quality. I have heard people say that they can hear the difference and even as an audiophile I was skeptical..... but my skepticism has been completely erased by what I am hearing with my own ears. I waited a few days to make sure I wasn’t just tripping before updating this review 🤣....but it has become clear to me how much a difference plugs made from the right materials actually make!!! I am 100% serious that the bass coming out of my Polk Signature Series tower speakers has at least doubled at the same volume. I can also now turn the volume up Way past my max volume before, without any distortion and much more clarity and less harsh highs. Everything just sounds warmer in general now which is amazing!!!! This is dangerous info for me... because now I’m thinking about making some really nice custom wires to see how much of a difference that makes 🙄🙄🤣 OK onto the review of the actual plugs here~~
These seem like decent connectors. I can’t tell if they are brass or copper, but they only have a slight hint of a magnetic property when testing them with a very powerful magnet. I was easily able to fit x2 - 14ga wires into it for bi-wiring purposes, including screwing on the collar. (As seen in my example pic) The gold plating on the tips seems legit and not painted like some of the plugs from Sewell... I have tested and tried quite a few plugs from Amazon and most seem to be crap. These however hold up better than most! These and the Monoprice 90° banana plugs with the black and red rubber sleeves. The latter are gold plated copper and have zero magnetic properties. (if you need 90° banana plugs)
UPDATE: still the best plugs I have found, but upon full install found two issues. One is a defect where a set of the plug threads for the barrel cover body weren’t cut right. The body’s do not tighten and stay loose because of that. Obvious issue for vibration with metal on metal...
The other issue is that even though these say they can fit different gauge wires, they seem to be geared more towards 12 or 10 gauge. I am using semi solid strand 14 gauge and find that unless I fold the wire over to make it double thick, the bolts use up all the thread and seem to become kind of loose inside the body. They won’t fully seat and keep spinning no matter how much you tighten. They seem to stay secure still but I just wonder about longevity over time with vibrations. So I just doubled up the wire and they seated fine! Not the worst issue in the world, but just kind of a pain since you have to strip the wire longer than you normally would so you can fold it over.
ANOTHER UPDATE: I had to remove these plugs from the wire to connect them to a crappy spring terminal amp while my better amp was in the shop. The issue I wrote about with the set screws "bottoming out" on smaller gauge wire became a more pronounced issue! I could not unscrew the set screws anymore and just had to cut the wires... So that means I will need to purchase more of these to replace the ones I cannot get wire back into. Not the best design, but still one of the best plugs I have found on Amazon.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on March 26, 2021
★★★★★ 5
Sturdy. Tight fit. No wobble
Size: 2 Pairs / 4 pcs
These are the best ones I’ve found. This order will connect one wire. Luckily that’s what I needed. If you’re doing more than one wire…
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 18, 2026
★★★★★ 5
Superior Design!
Size: 6 Pairs / 12 pcs
Delivery was lightning fast.
I tried a pack of two pairs of these banana jacks as a sample to see if these would meet my needs. The design of these plugs is superior. The design was exactly what I wanted because the speaker wire is secured with TWO set screws. Then I ordered an additional six pairs of plugs to hook up my subwoofer to my amp and speakers.
(I feed the audio output from the amp to the sub. The sub has a crossover that keeps the low frequencies and sends the mid and treble frequencies to my bookshelf speakers.)
I love the security of two set screws on each plug and love the barrel that screws on AFTER the wire is secured by the set screws. Most banana plugs have a hole through the shaft of the plug that receives the stripped wire. Then the barrel cover is screwed down to secure the wire in the plug. This design compresses the speaker wire but eventually the cap loses it grip and allows the connection between the wire and the plug to become loose. Then the transfer of the audio signal becomes poor and the speakers sound bad. Every month or two I needed to check all the banana plugs and re-tighten many of them for the best performance. The two set screws eliminate this problem. The set screws are quite small and take a little extra care in installation. You will need a small flat blade screwdriver to tighten them. I used the 1/8" flat blade driver from a set of jewelers screwdrivers.
These well made plugs are a bit pricier that many of the banana plugs available but certainly not the priciest plugs available. For me, the slightly higher price was more than offset by the security of the wire within the plug.
I'm not thrilled with the extra tight fit of the tip on the plugs into the jacks. It took a lot of effort to insert the in the jack. Actually I "greased" the pins (very sparingly) with with non-corrosion, conductive paste (Ox-Gard, No-Corrode, etc. Do NOT use any other grease.) Next time I'll use pliers to compress the pin.
My only quibbles are that the spring pins that go into the jack are very tight and that the plugs are only sold in quantities of two pairs or 12 pairs.
I recommend these banana plugs for all who are using the banana plugs and jacks for hooking up your speakers. It's a very convenient way of connecting speakers if your speakers and amplifier have the banana jack as part of the binding post. Further, it's much safer to use banana plugs since the possibility of shorting your amplifier with a stray strand of wire is practically zero. Easy Five Stars.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 13, 2018
recommand products
BMC Carbon Kit Supercar BMW M2/M3/M4 (G87/G80/G82) Airbox Cover & Filter Only - Glossy Paint Version
750.16
BMC 2013 Audi A1 2.0 TFSI Oval Trumpet Airbox Kit
171.94
BMC 19+ MV Agusta Turismo Veloce 800 RC SCS Carbon Racing Filter
154.62
BMC 2016 Fiat 124 Abarth 1.4L Oval Trumpet Airbox Kit
155.11
BMC 06-10 Audi TT/TTS/TTRS 2.0L TFSI Carbon Racing Filter Induction System Kit
1158.76