Style DPU-BHT piston seals are molded in Freudenberg AU 30000 urethane. Specifically designed as piston seals, these u-seals are engineered to seal on their outside diameter. They offer extended service life and maximum reliability in piston sealing. This high tear-resistant urethane demonstrates stability throughout a wide range of temperatures. In addition, this material is well suited to mineral and biodegradable hydraulic fluids as well as being resistant to hydrolysis.