Features: A 1*20/24-pin power supply tester for ATX/SATA/HDD power supply. Prevent electrical disasters by periodically testing power supplies to detect problems before they damage your computer, monitor voltage output. The green LED will illuminate when your device is running smoothly. This new ATX power supply tester can test 4PIN/6PIN/8PIN HDD power connectors and 20PIN/24PIN FLOPPY, very powerful. Rugged plastic, plug-in design, can test PC 20/24 pin, PSU, ATX, SATA, HDD. Specifications: Material: ABS Size: Approx. 9*7*2.8cm/3..54*2.76*1.1inch Color: Black Package list: 1 x Power Supply Tester Note: Power tester instructions: Power the power to be tested. Plug the 24P (20P) plug of the power supply to be tested into the 24P (20P) socket corresponding to the power tester. Check if the seven lights on the right (+3.3, -12V, PG, +5VSB, +12V, -5V, +5V) are on, all lights up is well. Plug the HDD plug to be tested into the HDD socket of the power tester to see if the two lights on the left (+12, +5V) are on, all lights up is well. Remove the HDD plug from the power tester, and then insert the P4 (P6/P8) plug into the corresponding P4 (P6/P8) socket to see if the left one (+12V) is on, all lights up is well. Pull out the P4 (P6/P8) plug from the power tester, and then insert the FLOPPY (floppy drive) plug into the corresponding FLOPPY socket to see if the two lights on the left (+12V, +5V) are on, all lights up is well. Remove the FLOPPY plug from the power tester, and then insert the SATA plug into the corresponding SATA socket to see if the three lights on the left (+12V, +3.3V, +5V) are on, all lights up is well. .