This track mounting solution includes the high-strength composite RAM ROD fishing rod holder, 6” spline post, and dual T-bolt track base. Compatible with the RAM Tough-Track and designed to not loosen while trolling, this track base makes an excellent addition to the left side of your boat. Paired with the included spline post, easily rotate the RAM ROD fishing rod holder 360 degrees while tilting the cradle forward and back to achieve the ideal angle. The T-Bolt dimensions are 0.48" x 0.95"