The aluminum body and rotor found in the Thunnus provide maximum strength for handling any saltwater fishing situation. The patented Baitrunner® feature acts as a secondary drag system, allowing anglers to feed out line in a tension-controlled free spool with the bail closed. The Thunnus also features a waterproof drag system, the Fluidrive® gear for smoothness when retrieving, the Super Stopper II® to eliminate backplay for solid hook-sets, and a large-capacity aluminum spool.