About this product: Quick Overview: Handy device for testing LED's. Simply plug your LED into the correct holes (all of which are marked) and push the button to see its brightness, illuminant color, etc.Features: Handy device for testing LED's (2-150mA). Simply plug your LED into the correct holes (all of which are marked) and push the button to test its brightness, illuminant color, etc. The top row is for 2 pin LED's with currents ranging from 2mA - 30mA. The bottom row is for 4 pin LED's (piranha LED's) with currents ranging from 20mA - 150mA. Lightweight & compact.