CRJ Full Speed 12V Voltage Step-Up USB to 3-Pin and 4-Pin PC Fan Sleeved Power Adapter Cable

I use a portable usb battery and one of my old computer fans with this cable to cool the inside my costume helmet. It works great.

Tested out a few fans and a pump with this cable.

Ordered a 5v cord first time.. This works great for the higher RPM computer fans-- in ANY type of build. ANYTHING you could need one for.

When it works it works great, it steps the voltage up to properly use a 12V .25A static pressure fan and I appreciate that. Unfortunately its making extremely bad contact and only works with someting putting pressure on the leads. Annoying.

Works well, would be better if it had a dial to adjust speed for PWM fans. The usb plug is large and sticks out when I connect this to my dongle, but overall it works as intended.

Had to use to power main cooling fan on PC when the water cooler control board failed.