Additional Details ------------------------------ Product description: DESCRIPTION: Chemlink 4" Chemcurb-e Kit Includes All The Items Needed To Create 4 Complete Penetration Seals. Very popular for solar rooftop installs! Suitable for up to 2" OD Pipes. Molded plastic interlocking curbs are quick and easy to assemble. Design allows retrofitting around existing pipes. E-Curbs are designed for use on all types of flat & low sloped roofs, including granulated modified bitumen, asphalt, coal tar B.U.R. (built up roofing), PVC, PIB, and TPO single ply roofing membranes. E-Curbs are highly versatile for sealing penetrations around solar panel mounts, HVAC, Electrical, and any type of structural supports. TPO Primer is required for use with TPO.