These small but mighty testers are two very important tools for every homeowner. The Gardner Bender GUSB-3300 USB Tester is a 3 function USB tester used for checking for the presence of voltage and testing for proper wiring and polarity. It features an LED that illuminates to easily indicate one of four different USB conditions: dead port, ok port, reversed polarity, and AC voltage presence. The GFCI Tester tests for ground fault interruption, open ground, open neutral, open hot, hot/ground reverse, hot/neutral reverse and correct wiring for standard outlets, GFCI outlets, and extension cords.

• Simple "go" and "no-go" designs
• Multi-color lamps indicate the status of the outlet or USB port
• Compact designs fit in a pouch or drawer for storage
• Must have testers for both DIYers and professionals