Cast aluminum plumbing vent pipe covers were first used on Airstreams and some Argosy trailers in the 1970s.  This version was seen in later years but is a good substitute for the earlier version or any trailer where you will be installing the vent pipe cover on a pitch or curved roof. 

Your 1-1/2" ABS pipe comes up through the roof. 

Use with VTS-1075 rubber gasket sold separately. Also, we recommend using a 4" x 5" square piece of aluminum insect screen domed over the top of your pipe and tucked into this stack cover.

This cap is usually installed with 6 Olympic rivets (VTS-179).