Lincoln Service Parts 1 › Lincoln Electric 9SM21923-7 CASE BACK INSULATION M21923-7 Lincoln Electric 9SM21923-7 CASE BACK INSULATION M21923-7 Sale Price: $41.51 Original Price: $47.74 CASE BACK INSULATION PURCHASE PRICE SHOWN IS FOR A QUANTITY OF 1 Add To Cart Added! CASE BACK INSULATION PURCHASE PRICE SHOWN IS FOR A QUANTITY OF 1