7/8″ O.D. Black Injection Molded Nylon Outside Eye End (273100-1) by Sea Dog. Top Cap. UV stabilized injection molded nylon top fittings connect to tubing and create an attachment point as part of a Bimini top system. Top fittings function as a pivot point for your canvas top. Available as a top cap or insert for ” or 7/8″ round tubing or as an insert for 1″ square tubing. Available in black or white.