PISTON RING STELL, HYDRAULIC PISTON RING SET The Sizes of the hydraulic piston ring steel are avalaible: PISTON RING90PISTON ... RING135PISTON RING140PISTON RING160PISTON RING185 Various PILOT VALVE SEAL are appliy for Komatsu, Cat, Hitachi, Kobelco, Volvo, Sumitomo, Daewoo, ... Hyundai ...also we can supply for these brand NOK, WYS, HALLITE, SKF, any separate seals, ...