3" IPS x 1" Wall Fiberglass Pipe Insulation. This Fiberglass Pipe Insulation is commercial grade with s pre-slit center for easy applications and a self-sealing strip for easy sealing.This 3" IPS x 1" Wall Fiberglass Pipe Insulation is made out of 1" thick compressed commercial grade, heavy density resin bonded fiberglass. The covering material gives your pipes a nice, clean look.