Through-the-wall dryer vent cap assembly, also known as a dryer outdoor vent damper. It is in excellent condition.
This assembly allows a clothes dryer's hot exhaust safely out of your home. It has a white molded plastic section that covers the exterior wall opening to protect the ducting from outdoor eleements like rain or wind. It features a built-in flapper door inside that swings open when the dryer is running and drops shut when turned off to prevent cold backdrafts or pests from entering.
There are pre-milled holes for screw mounting. Screws not included (you will need 4 screws). Note: I probably can find screws here for you for free but can't guarantee it.
It doesn't include an interior pest screen, but not needed unless you have a real critter problem on your property.