Flat o ring 1.Silicone FKM FPM VITON A VITON B GF GFLT GLT AFLAS HNBR... 2.High price performance ratio ... Item nameFlat o ring MaterialSilicone,,FKM,FPM,VITON A, VITON B, GF,GFLT,GLT,AFLAS,HNBR... ColorRed, blue, pink,white, black ... temperature resistance, chemical corrosion resistance of sealing materials in defense industrial airplanes and rocket, hose or other parts and automobile industry ...