Available in 8 sizes: 1-1/2" to 1", 1" to 1-1/2", 1" to 1/2", 1/2" to 1", 1/2" to 3/8", 3/8" to 1/2", 3/8" to 1/4", 1/4" to 3/8" Quickly change impact tool drive size 1-1/2" turn 1" of the meaning is: 1-1/2" that is the end of the card wrench position, 1" that is a bead position Made of high strength Chrome Vanadium Steel, with a hole for secure fixed Whole quenching heat treatment, durable high hardness Perfect for air tools, hand tools, impact tools, Manufacturer: SENRISE