12V Fan Speed Controller, Fan Power Adapter,USB 5V Step UP Boost to DC 12V Adapter, 5-12V Adjustable, with 3/4 Pin Fan Connector Cable, 4.8ft Length

love that it got a fan speed control wheel and power on/off button so that i can tweak my fan when when required. It’s also easy to install, just plug and play. Cable is relatively long (like around 2m after connecting both sides)

It's simple and has proven durable enough for daily use. Having the barrel connector makes it easy to test other DC equipment.

I didnt even know I needed it until I bought it. I have extra case fans from my computer builds. I used a case fan or another project of mine and this little switch came in handy. the length and power is great.

This is a cheap PWM controller, but it introduces power fluctuations that result in coil whine, even from high-end fans.

The media could not be loaded. I acquired the PC Fan Speed Controller primarily to test PC fans, given my interest in conducting product reviews on Amazon. This tool has proven to be surprisingly useful in this regard, providing the ability to test various fans before they are used in their intended applications. As someone who built a custom gaming PC filled with numerous RGB elements, I found the controller beneficial, not for the PC itself, but for the associated creative explorations. I've considered using it to control fan speed in future enhancements and engineering projects.An unexpected potential application came up with a side project I had in mind - building a larger external desk fan composed of couple dozen 120mm fans. This product suddenly made the idea a tangible reality. With the ability to bypass a PWM connector on a motherboard for controlling fan speeds when paired with other external devices, this adapter has opened up new possibilities. I wouldn't recommend this device for controlling fans within a modern computer system. That responsibility should be handled by the computer itself. Despite this, the product has proven its worth in ways I hadn't initially anticipated and I'd recommend it to those who understand the nuances and risks involved, such as product testers, inventors, and engineers.As you can see in the attached photos, this controller lets you circumvent the need for a PWM connector on a motherboard to control fan speeds, when paired with other external devices. I suspect this is how many product reviewers showcasing computer fans operate. The quality of the product was as expected - sturdy and well-constructed. The switch to control the fan mode (reverse and forward) was quite finicky, requiring some effort to operate. The cable length was sufficient for testing fans placed in front of me, and I can envision its potential use for managing fans positioned further away, like in my larger fan project. A point of curiosity was deciphering what the slider represented in terms of power draw. Adjusting the "fan speed" by sliding the wheel was simple enough, but I wasn't entirely sure what it meant. Was 100% on the controller equivalent to the fan's maximum capacity, or just a controlled speed set by the manufacturer?This product performs as intended - enabling the adjustment of a 120mm fan's speed without needing to connect it to a PC motherboard. While the application of such a product may seem limited, this isn't a drawback of the product itself. I would recommend this controller, but with a few reservations. The ability to reverse fan rotation was a concerning feature, as that's not how PC fans typically function. To alter airflow, a fan should be physically flipped around, not have its power supply reversed. Reversing the polarity of a PC fan could potentially damage the fan, causing the motor to spin the wrong way or placing undue strain on the bearings. This could result in increased noise, reduced performance, or even complete fan failure over time. Ensuring correct polarity before powering any electronic device is critical to avoid potential damage.In light of this, I would recommend this product to product testers, inventors, and engineers who understand the nuances and risks involved. However, for the average person building a computer and looking to control fans externally, I would advise caution. The risk of damaging equipment, even a simple 120mm fan, seems too high and not worth taking.

Super easy way to tap power from usb port to power a 12V computer fan. I use it to control a PWM fan and it works really well, allowing me to adjust full spectrum of speeds.

Not much to say about this other than it works as intended. Variable speed control but I’m not sure it’s actually outputting 12v. It is still perfect for what I needed and I’d buy this again if I have another project.

I've bought it to adapt a 4-pin 80mm fan to be used with an USB port. Turns out it works really fine. I've tried with a 120mm fan but the USB port won't provide enough power I guess. Since I needed it to be used with 80mm fans, I haven't tried but maybe using it with a 12V USB power adapter could work with 120mm fans.