The Plumbright Hose Union backplate completes the wall tube and consists of a length of 15 mm copper pipe attached to a 12.7 mm female threaded tap-mounting flange. Its most common application is for use with a garden hose union bib tap. Creates a tidy finish to an installation of an outside tap. Length of copper tube 450mm Total approximate length 500mm 1/2" Female iron connection Quality product.