Vented Cap for new style furnace flu (Female).
Was having problems with birds trying to build nest in my furnace flu.
This cap just presses on, no glue needed.
My furnace flu has two 4 inch PVC pipes outside near the ground and terminate one with a male connection and the other female.
Will post the male vented cap when completed and tested.

Printed at .2 layer height and at 10% fill.
No raft or support is needed to print.
Truly any setting would do, within reason.
There are a few of the vent boxes that push into the sidewall of the pipe connection.
I allowed this because I wanted as many holes (vents) as possible so not to restrict air flow.

Used 123D Design