Compatible with Smart Track Bayonet Pin rudder housings (Bayonet pins are 42mm long). This style of sleeve has a flange at the top.

Not included in the Bayonet Housing kits so will be needed if the kayak / surf ski does not already come with a sleeve.
Installs into kayaks with a flat area on the rear deck. A 1/2" hole (or slightly larger) is required (start small and enlarge if needed!).