30 function multi tool packed into a custom protective case that mounts to any round tube or seatpost 25 mm 33 mm with a secure quick release strap the chain tool is compatible with single and multi speed chains up to 12 speed not including campagnolo 11 speed hollow pin chains features chain pin breaker disc brake spacer chain pins and links compartment specifications added features secondary chain link fence chain pin breaker air release button sand paper mini ham