JL Industries KeyCurb™ Rooftop Support Systems. Solid rubber strut with galvanized channel bolted to top of curb and 8”, 12" or 16" channel frame. The JL Industries KeyCurb™ strut series RKCSN1 rooftop support is manufactured with solid molded 100% recycled UV-resistant rubber base, pre-galvanized channel, and comes with fastening hardware,...