This Automatic Circuit Identifier comes with a digital receiver and a 120-volt-240-volt GFCI receptacle tester. Now you have a unit that automatically indicates the right breaker for quick and easy breaker identification and plus verifies the presence of power. It works on 120-volt-240-volt circuits. A noncontact voltage sensor is included. The GFCI receptacle tester is a part of this kit as well and verifies proper wiring. See attachments for additional information.