... FPM, etc.2. Characteristics: good physical and chemical properties flat o-ring. 3. Hardness: 30~90 shore A or ... exactly upon your request or standard tolerance. 5. Color: black, transparent, green, red, yellow, grey, purple, pink thick o ring ... FDA, NSF, KTW, WRAS, LFGB, etc. 8. Applications: automobile flat o-ring, electrical appliance, mechanical, industrial, construction, household, medical and ...