Male O-Ring Seal Fittings are a critical component of hydraulic hose end fittings and marine hose fittings. Custom Hydraulic provides a large selection of Male O-Ring fittings that meet or exceed U.S. Naval requirements. Our O-Ring fittings are designed to meet a variety of MIL-SPEC and SAE standards for use with hydraulic hoses. Browse the list below to identify the correct Male O-Ring fitting for hoses by type and group classification.