Makes testing your ATX power supply a snap! This simple tool lets you test ATX12V (v1.3 and v2.0) power supplies without fussing with voltmeters or probes. Simply plug the power supply outputs into the 24-pin (or 20-pin) connector to verify the voltage of each rail. Colored indicator lights make diagnosing problems easy: green for normal, yellow for insufficient, and red for over-voltage conditions.