This is a complete replacement for old Thetford waste dump valves.   It has a flat top for direct mount to your holding tank.  It has a 1-3/8" long 3-1/2"O.D. slip fitting on the bottom outlet side.  Blade is plastic.  Comes with handle.  Top eal and four mounting screws are included.

This is version 08708 of Thetford valve 01447. Every Thetford valve ever made says 01447 on it, so you can't rely on the number molded into the plastic to guide you in selecting the correct version.