Replacement crash bobbin insert 50mm x 25mm. Made from high impact high density polyethylene, the insert screws into place using with a coarse thread for added strength and an M6 locking screw for added security. (replacement inserts should be screwed into place and drilled 5mm dia through the M6 threaded hole in the outer then the screw should be screwed into place) Product Code: SESCBI5025-X