The Taco Grand Slam 170 Center Rigger uses Taco's spline lock technology for secure outrigger elevation. Designed for use with standard 1-1/8" butt OD outriggers, the center mount locks every 18°. Derlin bearings and stainless steel internal locking mechanism offer smooth adjustments while providing secure positioning and preventing movement. The rugged, sure-grip knob adjusts and locks in desired height as well as laydown position for safe trailering and navigation under bridges. Rugged, sure-grip knob adjusts & locks in height | TACO Marine Taco Grand Slam 170 Center Rigger, 1-1/8" OD