FRD HMPS Doors 50 mm shutters are made of 18 Gauge/16 Gauge G.I. Sheet with Vertical Channel. Stiffness, rigidly welded & mineral wool insulation / ceramic wool Insulation of suitable Density Flames are of cross section 150 X 60 mm / 125 X 60 mm / 100 X 60 mm /90 X 60 mm etc.These doors are test evaluated at ARAI (Govt. Of India) for 3 Hours as per BS 476 & IS 3614.Sizes are custom Made] .