Grand Slam 170-2 Center Mount Uses TACO&';s spline lock technology for secure outrigger elevation Designed for use with standard 1-1/8" butt OD outriggers Locks every 18Adeg Derlin bearings and stainless steel internal locking mechanism offer smooth adjustments, secure positioning and prevent movement Rugged, sure-grip knob adjusts and locks-in desired height & laydown position for safe trailering and navigation under bridges Stainless steel arm with locking feature ensures TACO outriggers remain securely in place This product may not be returned to the original point of purchase. Please contact the manufacturer directly with any issues or concerns.