Lincoln Service Parts 2 › Lincoln Electric 9ST13639 ROTARY SWITCH KNOB T13639 Lincoln Electric 9ST13639 ROTARY SWITCH KNOB T13639 Sale Price: $54.02 Original Price: $62.12 ROTARY SWITCH KNOB PURCHASE PRICE SHOWN IS FOR A QUANTITY OF 1 Add To Cart Added! ROTARY SWITCH KNOB PURCHASE PRICE SHOWN IS FOR A QUANTITY OF 1