Alemite 304810 is a straight air vent 1/8 in. Ptf SAE Spl short grease fitting with an overall Length of 1 in. And shank length of 0.19 in. It exceeds the 72 hour salt spray test. The vent opens at 1-3 in. Water pressure (1 in. Of water = 0.03613 psi) and features a special steel cap that prevents water or dirt from entering the grease fitting. The vent's trivalent clear zinc plating protects against corrosion. The use of this fitting helps prevent fluid leakage. Alemite vents are used with transmissions, speed reducers, axles, gear housings and other similar applications. The vent is placed above normal lubrication level to allow air to escape when internal pressure rises. As the inventor of the Zerk fitting, Alemite is a recognized global leader in supplying fittings for automotive and industrial use. Alemite fittings conform to SAE J534 standards for automotive OEM use and Alemite Manufacturing is TS/ISO 16949 certified.