CONNEX chain 12-speed, 1/2“.; x 11/128 self-service package, with a width of 2,10mm, these chains are compatible with all common 12-speed shifting systems.High-quality materials and the extremely shaped outer plate promise a long service life and outstanding shifting properties.The enclosed Connex link makes it easy to mount and dismount the bicycle chain without any tools! Pin length:5,30mm .SPECIFICATIONS:-´´12sE´´, nickel, suitable for e-bike, 126 links, weight:285g.