Flange Gasket, Ring, 1 in Pipe Size, 2 5/8 in Outside Dia., Bolt Holes 0, 1 5/16 in Inside Dia., Metal Detectable No, Material of Construction Flexible Graphite with 316 SS Insert, 1/16 in Thickness, -400 Degrees to 975 Degrees Temp. Range (F), Color Dark Gray, Standards ASME B16.21