These state-of-the-art, Multi-tap Power Transformers come with variable voltages (12 to 15 volts) that allows you to customize the voltage for each individual run if needed. A timer (sold separately) can be plugged into the unit to manually control hours of operation. The transformers are primary fuse protected, housed in a stainless steel case and ETL listed for UL standards. All units are X-10 ready and best of all, they are backed by the Intermatic's lifetime warranty!