Always used with an accessory (ratchet, sliding T handle, socket, combination and open end wrenches), it helps to remove oil filters from trucks and cars. Versatile, it has a 3/8'' internal square socket with a 1/2'' or 21 mm hexagonal adaptor. The special steel body and legs ensure the product's resistance. In addition, the legs and adaptors are hardened, providing special hardness at the region where the most effort will be applied during use