Reducing Nipples have two male threaded ends and are used to connect threaded ABS fittings or valves with one diameter smaller than the other.
BBB - ABS Pipes & Fittings
The reducing nipple is a short stub of a pipe consisting of a short straight piece of pipe, usually provided with male pipe thread at both ends, for connecting two different sizes female threaded fittings or pipes.
304 Stainless Steel Fittings
The reducing nipple is a short stub of a pipe consisting of a short straight piece of pipe, usually provided with male pipe thread at both ends, for connecting two different sizes female threaded fittings or pipes.