Service Kits are standard, and contain polyurethane and Buna-N seals for standard hydraulic service. These seals are suitable for use when hydraulic (mineral-type) oil is the operating medium. The recommended operating temperature range for Class 1 seals is -10½F (-23½C) to +165½F (+74½C). The seals contained in these kits are supplied as standard on all Series 2H,* VH, 3L and 7" and 8" bore 3H cylinders manufactured after Sept. 30, 1990 for Class 1 hydraulic (mineral) oil service. The seals contained in these kits are interchangeable for hydraulic (mineral) oil service on all Series H,* 2H,* VH, L, 2L and 3L cylinder.