Horizontal Rail Mount - Fits Standard Round Rails 7/8 or 1 (22mm or 25.5mm)These incredibly strong rail mounts have a unique pivoting design which allows them to mount to straight or curved rail or across the corner of a stern rail. Made of 18-8 stainless steel and 356 anodized aluminum, they instantly detach without tools for compact storage.This product may not be returned to the original point of purchase. Please contact the manufacturer directly with any issues or concerns.