COOPER B-LINE's 5 x 6 x 20.2 in Dura-Blok rooftop support. Made of 100 percent recycled rubber which qualifies for LEED credits. Does not penetrate and has no sharp or abrasive edges, helping extend the life of the roof. When used in combination with B-line strut and pipe hanger systems, Dura-Blok supports offer a total solution for rooftop applications such as solar PV mounting systems, piping, HVAC equipment, rooftop walkway systems, ducts, conduit, and cable tray supports.