Shown is a General Electric socket type timer, type TGW-1, 120 volt, 60 Hz, 35 amps. Adjusting the clock mechanism is accomplished thru the slotted knob that extends thru the glass, but the glass must be removed to set the on and off switch actuators or pushers on the time switch's dial. Works very well and I use it on my Christmas lights since it's weatherproof.