Am-Tech 3pc Socket adaptor Set. Made from heat treated Chrome Vanadium steel for durability. Rust resistant black oxide finish. Set includes sizes 3/8″ (F) x 1/4″ (M), 1/2″ (F) x 3/8″ (M), 3/4″ (F) x 1/2″ (M). suitable for use with most corded cordless or air powered impact wrenches.