Gebildet 2 Pack USB Fan Power Adapter Cable with Switch, USB to 3/4 Pin Case Fan Adapter Connector with ON/OFF Switch

You need to read the fine print and reviews about capacity. I'm using it to power a pair of 140mm fans for a cooling station under my router. It suites my needs fine because I am using it at about 30% on the dial to provide cooling which is absolutely silent. Antec Tranquil fans are high quality and only brand I trust around for a while that truly makes a silent fan. The speed control is quality and sweeps almost 360 degrees with a off position...real nice. My fans come on at about 15-20% of travel. If I turn it up all the way, the fans start to faulter, one fan works okay, but only comes up to about 80% of max capacity. With both fans, I can get up to 50% of travel, which is fine for my application. Specs do warn that this is not for 12V USB fans. Switch has a bit of a radio shack look to it, but my computer is half old school anyway, I think its fine.

They did exactly what I hoped they would -allow me to utilize quiet case fans in place of my desktop fans which are too loud, and give me complete control over the fan speed. Very pleased with this purchase.

Used to convert an old pc case fan to a cooler for my stereo that was suddenly over heating. Worked like a charm.

I'm using these to power some 120mm fans cooling mini PC's. They work for this although power wise it seems only usable for half of the rotation. Most fans I tried did not spin up until half way, and full speed is definitely not full fan speed, which honestly I did not look too closely at what voltage these are putting out. This actually works out fine for my usage as I can set it full speed and get the air movement I need with no noise even with my worse fans. The only thing that isn't great is these stick out quite a bit, so they are not efficient with space if your equipment is in tight areas. For the price I can't complain.

I return a lot of junk on Amazon. This is not junk. Well worth the money.

Fit my 40mm fan and worked perfectly. Convenient two pack for a good price

i used for repurposing old PC fans.

The Gebildet 2 Pack USB to 3-Pin / 4-Pin PWM 5V USB Sleeved Fan Power Adapter Cable is a practical solution for anyone needing to power PC fans via USB. Each cable is well-built with sleeved wiring, ensuring durability and a tidy setup. The adapters are versatile, supporting both 3-pin and 4-pin PWM fans, providing flexibility for various fan configurations. They deliver consistent 5V power, effectively cooling components while maintaining a quiet operation. Whether you're setting up additional cooling for your PC, Raspberry Pi, or other devices, these cables are reliable and easy to use. A solid choice for DIY enthusiasts and tech-savvy users alike.