Cloth Inserted SBR - 70A - Rubber Sheet - 1/8" Thick - 4" Width x 4" Length - Black (8 Pack) Reinforced elastomer with minimum tensile strength of 500 PSI (4 MPA) Made from Styrene Butadiene rubber (SBR rubber) this is a smooth black rubber This reinforced sheet rubber is available in 4 thicknesses (1/16", 1/8", 3/16", 1/4") Cloth inserted rubber sheet durometer has a 65-75, with limited flexibility and low elasticity This reinforced sheet rubber has an approximate weight of: 1LB per square foot in 1/8" thick