Hand Controlled Tyre Changer Assist Arm Control Air Valve.1 Brand new tire changer arm control air valve with premium quality. 2 Made of high quality aluminium alloy material for high durability. 3 The middle position can be spring centered.The On/Off switch can be self reset. 4 Professional manufacturing, perfect replace the old one. 5 The product has been tested strictly and advanced, durable in use.