OBT Amercian Axle feature: 1) Standard Center distance of chamber GM is 243mm, other length is available 2) 5" Round Axle - 16mm standard wall thickness. 3) Axles are available with single wheel fixing or without brake. 4) Standard track length - 1850mm, other track lengths are also available. 5) Other wheel fixing are also available. 6) All axles include standard manual slack adjuster, auto slack adjuster is optional.