This is a Large In-Line Fuel Filter from Dubro.
Constructed of two threaded aluminum parts which separate for ease in cleaning. Includes a 130 micron mesh screen filter to filter out the smallest of particles and an O-ring to properly seal against leakage. Suitable for gasoline or glow fuel. Is installed in fuel tubing between the carburetor and fuel tank. Fits 1/8 in. diameter tubing.