Vintage TRUMBULL 3 GANG 100 AMP 250 VOLT KNIFE SWITCH, 

SLATE BASE, COPPER, 14.5" X 8.5" X 4", TRIPLE FUSED

Very large and heavy. It has a slate base that has a few scratches. This piece measures:

14.5" X 8.5" X 4" on the base. It is in very good conditions. 

These are no longer available and are special order/manufacturing.

TRUMBULL Electrical Manufacturing (Plainville, Conn, USA)