Top Fittings create an attachment point and function as a pivot point as part of a Bimini top system. For use as a top cap for 7/8-1-1/8 round tubing or as an insert for 3/4 or 7/8 OD tubing. Also available as an insert for 1-1/4 square tubing (1 x 1 inside dimensions) commonly found on pontoon boats. 1/4 or 5/16 pin size. Set screws can be purchased separately (299999-1). Requires 1/8″ Allen wrench to install. Constructed of corrosion resistant investment cast 316 stainless steel. *Stainless tube wall thickness 0.049.