The Parker A-Lok BF-B series compression tube fitting back ferrule is made of brass, and helps connect tubing to a fitting. This is the back ferrule of a ferrule set and helps provide a leak-resistant seal in high-pressure applications. It is made of brass for corrosion resistance, ductility at high temperatures, and low magnetic permeability. It is for use with Parker A-Lok twin ferrule compression fittings and pairs with front ferrule part number FF-B in a set (sold separately).Pipe and tube fittings are components used for connecting, terminating, controlling flow, and changing the direction of piping in many different industries. Compression fittings do not require tools or sealants, and are useful in installations where a heat source, such as a soldering torch, is prohibited. When purchasing fittings, consider the application, as this will affect material type, shape, size, and required durability. Fittings are available threaded or unthreaded, in many shapes, styles, sizes, and schedules (pipe wall thickness).Parker Hannifin manufactures electromechanical, hydraulic, and pneumatic motion technologies and systems for fluid handling, filtration, sealing and shielding, climate control, process control, and aerospace applications. The company, founded in 1918, is headquartered in Cleveland, OH.