Pinnacle series Piston Assemblies are available both in single and double acting type.. Piston rubbers of Piston assemblies are manufactured by using very high strength polymer with very tough fabric backing. Special care is taken for accurate dimensions of Piston hub and formed from high grade steel to ensure very long life. SEPL,s Piston assemblies give very long life even under extreme working conditions. pistons are fully interchangeable with other API standard designed pistons and deliver maximum performance in almost all drilling conditions.