The PET1 features variable sensitivity that lets you check for AC voltages from 12-volts all the way up to 600-volts. You no longer need to purchase two different instruments. Its continuity feature allows you to quickly check non-energized circuits using the sensor tip and one finger. This allows you to determine if controls and contactors are connected, check light-bulb filaments, verify fuses, check for ground faults or identify which wires go where in a mess of wiring. Detection is positive and trouble-free. you can hear the PET1's loud and clear detection tone and see its supper bright LED indicators even if you're in a noisy, poorly lit industrial environment.