About the Concrete Pump Rubber Piston ram , we have usual Putzmeister, sany, zoomline , schwing, and so on brands rubber piston seal. We also have CIFA concrete pump integral piston ram. We have natural rubber material piston, also have polyurethane material piston, And we can also customrized to produce the rubber ram with one layer of fabric. Our rubber piston is pure natural rubber material. Service life is 20000cbm-30000cbm. And working pressure is about 180bar. this is CIFA dn230 size ,we also have Cifa DN200,DN260 and so on sizes!