Filling filters and tank filler necks with breathers from the SMBB series made of metal/steel for mounting on hydraulic tanks and containers. Allows permanent venting while protecting against contamination entering the system. Cap diameter either 47 (1.85") or 80 mm (3.15"). Bayonet version with three-hole or six-hole connection as per DIN 24557-2. With high-quality STAUFF zinc/nickel coating. Options, accessories and spare parts such as pressurisation, filling screens, dipsticks, air filter elements, adaptors, adaptor sets.