This Socket Assist tool set is a 12-point design for better finger grip. The set includes 3 different sizes: one (1) 1/4" X 1/4" model, one (1) 1/4" X 3/8" model and one (1) 3/8" X 3/8" model. They are made from quality chrome moly steel. These unique adapters are very essential for use on bolts with very tight clearances such as spark plugs and header bolts. Simply plug a socket assist adapter into a standard socket, and you are ready to work in tight spots. No more banging around with a clumsy socket wrench and shredding your knuckles. a must for every tool box. Sold as one complete set. Backed by a limited 30 day factory warranty.