a collar for 4 inch flexible ventilation conduit allowing you to mount ropes to your vent and retract or lower it when needed. it is one file printed two times.
the Vent Hood can be found here https://www.printables.com/model/1388244-flaired-vent-hood
I used these Pulleys from Meister Edel https://www.printables.com/@MeisterEdel
The author marked this model as their own original creation.