This Intermatic T101D89 24 Hour Mechanical Timer Wall Switch is a heavy-duty switch suitable for wall, interior, and exterior use. It features a dial, switch, and digital control style, with a single pole single throw (SPST) contact configuration and a maximum amperage of 40 A. The switch is made of metal and has a gray finish, with a rectangular box shape and a size of 7.8in. height and 5.125in. width. It includes features such as vacation mode, indicator light, illuminated, timer, auto-off, dusk-to-dawn cycle, and is tamper-resistant. The switch is compatible with incandescent bulbs and has a voltage of 120 V. It comes with a cover and is easy to install with wall snap-in mounting style.