Kinesis Dropout 12This mech hanger fits:Aithein Disc (QR Version).4S Disc (QR Version).CX Race (QR Version).CX1.Pro6 v2.Please note: this dropout will not work on the following:Aithein rim brake - requires Dropout 10.Pro6 v1 - requires Dropout 7.CX Race with Thru Axle - requires Dropout 15.4S rim brake - requires Dropout 3.4S Disc with Thru Axle - requires Dropout 15.