Alpha SR2611F Series Rotary Switch 1P 12W - 2P 6W - 3P 4W - 4P 3W Select 12g

The switch style is rotary, with a selection of 1P 12W, 2P 6W, 3P 4W, and 4P 3W options to choose from. ie if a switch has 12 positions then you can insert the stop set washer to elect any stop position from 2 to 12.

eBay