Sea-Dog Nylon Square Tube Top Insert - Black - 1". 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. Features of Sea-Dog Nylon Square Tube Top Insert Injection Molded Nylon Tube Outside Dimensions: 1" (7/8" x 7/8" Inside) Square tube Top Insert Quick and easy installation Package Contents: Sea-Dog Nylon Square Tube Top Insert Sea-Dog 273580-1: Nylon Square Tube Top Insert - Black - 1"