It is rated to 6 amps. Be sure to read the rating on your current switch or add up the draw of your light bulbs to determine whether this is adequate.
The threaded portion extends 3/8" from the top of the switch base (1" from the bottom of the base).
The switch comes with a metal knurled knob. The old plastic knob does not fit this switch.
Some customers report this works well on the 1965 and 1966 rectangle diffusers too.
Wiring Tip: The 3 leads are labeled L, 1 and 2 on back side of black base. L is the black wire and it goes to your line voltage (hot/positive). The blue and red wires go the bulbs.