Wera Zyklop 8790 HMA 1/4" Socket, Hex head 4.5mm x Length 23mm Features ball intercept ring and for use with hex head fasteners, 4.5mm x 23mm socket With a brushed chromium plated finish Sockets have a ball intercept ring and rear end knurling for reliable manual precision. The Zyklop sockets can be used for both manual and machine work. Lighter and more convenient, these sockets vastly improve productivity. Limited Lifetime Warranty, German Engineered