The most versatile track system on the market that features adjustability throughout. Besides using for key trolling fishing components like downriggers, rod holders, bird trees, & planer masts, tracks can also be used for net holders, tool holders, rod storage racks, fishfinders & general use components like grills, beverage holders, cleats & antennas. Think about future possibilities when deciding on track length. Adding additional components is easy if extra track is initially purchased & inserts can be put in for use as a step until needed for components. WARNING: For shorter tracks used with downriggers, check the underside of your gunwale or transom to see if it is thin or already reinforced. If it is not reinforced, a backing plate should be used with the track to protect the boat from damage. Besides providing versatility to your boat, a track system can also SAVE YOU MONEY. When ready to sell your boat, a track system keeps it's value without having to include your valuable components. Simply move your components to your new boat's tracks & put inserts into the tracks on your old boat. No unsightly holes left that devalue your boat & no repurchasing of your components!! Inside width is 3". Outside width is 3 1/2".