The beauty of this system over using an adaptor is that the two aluminium cups thread into each other so they lock onto the frame

Attachment system for a full face or open face helmet

Using a stiff material but enough flex so they bend on impact

Original ISCG

Bikeyoke Willy Silicone Seat Clamp Cover - 30.9-31.6mm - Black PLP|EMTB Optimised The beauty of this systemDon't forget protection! If you ever suffer from getting dirt, dust, and water down inside your frame, it's likely coming from the tiny gaps around under your seat clamp. Well, there's a solution to that! The Willy from Bikeyoke provides a watertight seal around your seat post and seat tube, prevent any of that nasty crud from getting in and wreaking creaking and corrosive havoc inside your seat tube.