There are two cap styles for RhinoTube dock fenders:
TabCap
The TabCap allows you to secure the Rhino Dock Fender to all surfaces with screws, or nut and bolt. Use the TabCap to attach the dock fender to a post, beam, upright, wall or cross member.
Flat Cap
Flat caps are recommended for use on upright metal posts. Fenders using flat caps are usually attached to a post with a metal bracket.