Backup O-Ring, Material Buna-N, For Use with AS568A Dash No. 351, Thickness 0.076 in, Radius 0.262 in, Axial Thickness 0.06 in, Actual Width 0.183 in, Actual Inside Dia. 4.778 in, Cross Section Shape Rectangular, Durometer 90A, Durometer (Hardness) Rating Hard, Color Black, Temp. Range -40 Degrees to 250 Degrees F, Package Quantity 10