Brass running nipple extra long 1/2 inch BSP x 6 inch long.
Although it's called a 6″ long nipple, it is a tiny bit smaller than 6″
Male thread along entire length.
BSP (British Standard Pipe Thread) sizes don’t match up with what you would measure using a ruler. Have a look at the BSPT link at the bottom of this page for more information about how plumbing threads are measured.