• Natural rubber (NR) - Excellent for water based liquid at room temperature, highest mechanical resistance • Neoprene (CR) - Good balance between chemical and mechanical resistance. • Nitrile (NBR) - Excellent resistance to oils and fats. • EPDM - Best for hot fluid and CIP cleaning. Excellent for acid and alkaline fluids. • Silicon (VMQ) - Best for high temperature but low mechanical resistance.