Model GS-RM - Rail Mounting: (Non-Permanent) Takes seconds to put in place and seconds to remove, then store when your boat is running. Gullsweep performs best when it is level to the water. - Place vice clamp over railing & tighten so it is vertical to the rail. (Option, put tape around rail before mounting to indicate where GS-RM should be mounted, and also to protect the rail.) - Adjust center support pin to be vertical to the water & tighten adjustment nut. - Place your Gullsweep on the support pin, adjust, if not level. - If clamp is left on rail, remove center pin to avoid injury! Model GS-RM - (up to 1-5/8" dia.) Center pin (shown) is not included with GS-RM because it utilizes the standard pin that comes with a Gullsweep (GS-1).Features & Specifications UPC: 0648661000000 Description: Rail or pipe mount