... power supply tester is a robust voltage, tester for PC-power supply ATX, BTX and ITX compliant, power supplies can be tested ... …, check +12V, +5V,+3.3V;SpecificationVoltage source: 20/24 pin (ATX-connector)Voltage test: +12V,-12V,+5V-5V,+3.3V,5V ... : Floppy, HDD, CDROM, SATA, 4 pin(p4),8 pin(Dual-CPU). 6 pin (PCI-Express) LED power supply tester