C10 Rooftop Unistrut Rubber Support. Unistrut is a Steel U shaped support designed to mount all kinds of parts. The enamel finish over steel construction provides durability, and the pre-drilled holes accommodate mounting in any area. This C10 Rooftop Unistrut Rubber Support is a designed to protect the pipe or whatever is being supported on the unistrut from rubbing against the metal. This Rubber Support functions as a protective barrier that gives the unistrut and support added life.