we are manufacturing ,exporting & supplying butterfly valve rubber seal standard sizes as well as customer requirement.we supply maximum 1'' to 24'' seal. construction material : nitrile(nbr)fluorocarbone(viton)silicone (vmq)flurosilicone(fvmq)natural rubber (nr)ethylene propylene (epdm)styrene butadiene rubber ( sbr)chloroprene(neoprene)sample availability : yes.