Nylon Square Tube Top Insert - Black - 1"Top Fittings connect to tubing as a Top Cap or Top Insert for 3/4” or 7/8” round tubing or 1” square tubing. Top Fittings create an attachment point and function as a pivot point as part of a Bimini top system. Pin size 1/4”. Constructed of UV stabilized injection molded nylon. Available in black or white. *Stainless tube wall thickness 0.049”.