For fixed spool reels. Heavier duty then the thumb button and can handle serious power casting. The canon is fitted to the underside of the rod butt directly above the reel spool.
The design of the canon reduces line 'slap' on release and cuts down on crack offs causéd by loose line catching the butt ring.
A canon takes the pain out of fixed spool power casting and can help to add yards to your cast.