Tech Research Power Transfer Switch 120/240This Surge Guard model is a basic automatic transfer switch. It is generator dominant and transfers to generator power automatically when energized after 30 second delay. Once the generator is shut down, shore power activates after a 3 to 4 second delay.Features:Generator Dominant And Transfers To Generator Power Automatically When Energized After 30 Second DelayTime Delay At Power UpMechanical Interlocking ContactorsLimited 90 Day Warranty Weight: 0.1000 Type: Automatic Function: Transfer Power Between Shore And RV Generator Voltage: 120/ 240 Volt Ampere Rating: 50 Amp Terminal Type: Screw Length (IN): 7.78 Inch Width (IN): 5.1 Inch Height (IN): 9.33 Inch Color: Silver Mounting Type: Wall