"To match our new Thru Axles we have made our own derailleur retention bolts giving you the freedom to either colour match your new Thru Axle or to get wacky and mix the colours.
We have made retention bolts available to fit either the UDH system or the direct mount T-Type system. The UDH system has two parts; the UDH hanger (not supplied with the kit) and the UDH retention bolt which secures the hanger to your bike. The T-type bolt simply bolts through your T-type mech and frame.
Our T-type retention bolt is not compatible with GX mechs."