... brass nut 2)HPb58-3 or HPb59-1 DescriptionCompression fitting/PEX fittingsBrass compression fittings are composed of brass body, brass o-ring ... pipes, plastic-covered copper pipes, stainless steel pipes & fittings and PE-X pipes, covering more than 3000 types of quality products ... pure material, providing high quality, complete series, and best services" . Compression fitting, Equal Straight