Scotty 339 Power Lock Rod Holder. This Power lock includes a No. 449 Portable Clamp Mount. This powerful clamp has a maximum 2″ opening and makes your Power lock Rodholder instantly portable. Made from super tough re-enforced engineering grade nylon. Includes the stainless steel fasteners required to mount the rod holder to the clamp. A popular mounting choice for canoes, tin boats and even dock rails.