Lincoln K and KP Numbers › Lincoln Electric KP1921-1 GUN TUBE ASBLY, 68 DEG. Lincoln Electric KP1921-1 GUN TUBE ASBLY, 68 DEG. Sale Price: $333.99 Original Price: $374.07 GUN TUBE ASBLY, 68 DEG. PURCHASE PRICE SHOWN IS FOR A QUANTITY OF 1.000 Add To Cart Added! GUN TUBE ASBLY, 68 DEG. PURCHASE PRICE SHOWN IS FOR A QUANTITY OF 1.000