This 3D-printed vent is designed for a kitchen exhaust fan with a 4" duct outlet. The model consists of three parts: the first part is embedded into the wall, followed by a cover with slots for flaps that lift when air is pushed out and close when the fan is not in use, sealing the outlet.

For best results, I recommend using a low layer height to ensure smooth movement of the flaps. However, the flaps are designed with enough tolerance to allow for easy sanding if needed. No supports are required for printing this model.