NoctuaNF-S12A PWM, Premium Quiet Fan, 4-Pin (120mm, Brown)

High quality. Effective cooling at very quiet levels with a range of mounting and connectivity accessories. Also worth noting, Noctua honour their generous warranties.

This is the king of quiet PC fans. I checked specs on a number of them, and none match this for both noise levels and airflow.It runs at a maximum of 1200 RPM, or can be limited to no more than 800 RPM using the provided low-noise adapter. Also provided is an extension cable, screws, and rubber mounting devices that can take the place of screws, providing a mounting system guaranteed not to have any vibration noise. All provided in a stylish book-like package, with a nicely laid out instruction manual.Performance is excellent. It's extremely quiet while still moving a good amount of air. It looks good too, if you're into that sort of thing. Makes a change from plain boring black or grey devices.Installation is easy enough using the screws provided. The rubber mounting devices are a bit trickier, especially if you're trying to install the fan in a cramped PC case and/or where you can't get full access. You need to pull them through the screw holes, and they are a tight fit, requiring them to be wiggled around to get them fully through the holes. This is OK if you can get full access to the holes, but can be very hard if you're trying to install it in a tight place.If you're trying to lower the noise of your PC fans, or any device that uses (or can use) a 12cm / 120mm fan, then I know of no fan better than this one.The only downside is the price. It's definitely priced for the enthusiast market, and is packaged as such: everything about it shouts quality, high-end product. That's fine, but I likely would have bought a couple more if I didn't have to keep paying for stuff I don't need. It's a shame that they don't offer a 'bare' version that doesn't include the accessory pack. While it's well put together, and will be appreciated in many installations, there are likely many users who, like me, only need the fan, and won't use the provided screws, rubber mounts, extension cable or low noise adapter (all of which can be bought separately if the buyer later changes their mind about needing them.)Noctua really should consider also making the fan available on its own so that users who don't need all the other stuff don't have to pay for accessories and packaging they really don't need. I suppose they prefer to be seen as a luxury brand, but that's definitely costing them a few extra sales, at least from me.

TL,DR: BUY THEM!My build:Cooler Master Cosmos II CaseASUS Rampage V Edition 10 MotherboardEVGA SuperNova P2 1600w ATX PSUIntel Core i7 5960X ProcessorCorsair H110i GT AIO Water Cooler + Thermal Grizzly Kryonaut CompoundCorsair Dominator Platinum 3000Mhz 64GB DDR4 RAM (4 sticks) + 2x Corsair Airflow RAM fansMSI GTX 1080 Gaming X GPUSamsung NVMe SSD 950 Pro 512GBSamsung Sata 6G SSD 850 Pro 1TBWD Blue Sata 6G HDD 2.5" 2TBMy case came with 1x 200mm fan in the front intake. 2x 120mm fans in the bottom HDD tray. 1x 140mm fan on the top exhaust, and 1x 140mm fan on the rear exhaust. In addition to this, my water cooler came with 2x 140mm fans.I wanted a powerful yet quiet computer, so I bought the best parts I could afford, and I bought parts with capacity to spare because I didn't want to push my machine to its maximum limits. I wanted headroom to allow the components to room cooler. Yep, it's a waste, but I can afford the waste for silence.The PSU itself has more watts than I will ever need. But because of this, I can switch on the ECO mode and the fans will *never* run. I've been running this build for almost 9 months now and the PSU fans never needed to run even under load with an overclock (which I attempted a few hours just for fun, but returned to stock immediately after).The Corsair fans that came with the cooler are very good, but because they can reach 2000RPM they can get pretty loud. The Cooler Master fans that came with the case are also okay, but the truth is that Noctuas command high prices for a reason: they are awesome.I replaced the front intake with a 140mm NF-A14 PWM. Silent as a feather in a vacuum. I bought 2 more of these for the Corsair water cooler. I replaced the rear intake and the 2 HDD fans with 2 of these NF-S12A PWM fans and my computer is now silent even under load. It's amazing that I'm running this beast of a PC and it's completely silent.The Noctuas have a much improved motor and PWM IC design, so they have no commutation noise. PWM fans usually have this ticking sound, no so these ones. While I could live with the commutation noise from the Cooler Master and the Corsair fans, the Noctuas completely eliminates the noise altogether (or the frequency is above or below what human hearing can perceive).I have a tip: go on the Noctua website and check the product lines, they have a helpful filter and a page explaining the differences between models of 120mm fans, showing which ones are best for airflor, which are best for radiators, etc.They are expensive but worth every single penny. The accessories are super useful, I used 2 of the splitters and all of the extension cables. I also used two sets of the rubber mounting thingies.By the way, I made the changes about a week after I built the PC and I've been running these fans for months and they're still as good as day 1.

Even when running flat out these are pretty quiet. Well worth the money plus you get both mounting screws and grommets, cable extension and splitter. Well worth it.

Only had the fans a short while [1 week] but they have sunk my temperatures by 10-20degrees on idle whilst remaining at low noise. The only reason this is given 4 stars is because despite all the extras included in the box, the mounting option is soft plastic that bends so much, I can't fit it easily through the hole on all 4 sides due to case access restrictions for the top most case fan. So I gave up and used a screw...or at least tried to, but then realised these weren't able to fit the case I have [a now dated Antec P180]. A great case however - after 12 years. The good news is, 4 stars only for my experience. You might have a 5* experience. Advice to anyone buying these, expect to use screws if fitting this somewhere fiddly, unless you have ninja-like finger abilities :D