Flame retardant to 105 deg CIndoors or OutdoorsRequired by the NECThe rounded surface of the bushing prevents damage to wire insulationUsed with locknut to terminate threaded Rigid or IMC conduit to an outlet boxConduit insulating bushings plastic - indoor/outdoor size 2 inches High impact thermoplastic. Flame retardant to 105 degrees C. Use with locknut to terminate threaded Rigid or IMC conduit to an outlet box. The rounded surface of the bushing prevents damage to wire insulation. Required by the NEC. UL Listed, CSA Approved.