Lincoln K and KP Numbers › Lincoln Electric KP3155-1 MAGNUM PRO 550A, 1/4" RECESSED DIFFUSER Lincoln Electric KP3155-1 MAGNUM PRO 550A, 1/4" RECESSED DIFFUSER Sale Price: $16.11 Original Price: $18.04 MAGNUM PRO 550A, 1/4" RECESSED DIFFUSER PURCHASE PRICE SHOWN IS FOR A QUANTITY OF 1.000 Add To Cart Added! MAGNUM PRO 550A, 1/4" RECESSED DIFFUSER PURCHASE PRICE SHOWN IS FOR A QUANTITY OF 1.000