Flange Gasket, Ring, 4 in Pipe Size, 6 7/8 in Outside Dia., Bolt Holes 0, 4 1/2 in Inside Dia., Metal Detectable No, Material of Construction Graphite, 1/16 in Thickness, -400 Degrees to 975 Degrees Temp. Range (F), Color Dark Gray, Standards ASME B16.21