Seal for double-acting and single-acting cylinders Temperature range: -30°C to 100°C Material : polyurethane Symmetrical profile Max. 400 bar Series U type PU seals are replaced by Series SA-UN seals Types 605 and 663 have an asymmetrical profile* and are therefore only suitable for sealing piston rods. So never mount on a piston! Type 601 has a symmetrical profile* and is therefore suitable for both piston rod sealing and piston sealing. *Asymmetrical profile: the inner lip is shorter than the outer. *Symmetrical profile: both the inner and outer sealing lips are the same height. For an application specifically as a piston seal, please refer to type ZA-UN under piston seals.