'Spherical Washer, Steel, Black Oxide Finish, Fits Bolt Sizes M12, Male ID 13mm, Female ID 14.2mm, Outside Dia 24mm, Thickness 8mm, Thickness Tolerance +/-0.2mm, Radius 17mm, B68 Rockwell Hardness, Used To Compensate For Uneven Surfaces, Includes 1 Male Washer and 1 Female Washer, Pair'