100mm Insect Repellent Duct Cover

When connecting the duct of the laser processing machine out of the room, I connected a duct with a diameter of 100 mm.

The rain breeze can endure. But the problem is an insect.

Because there is no good net, I made it with a laser processing machine. Even 3D printers can be created without problems.

Attaching to the duct, using a bellows, does not require bonding when pushed in. It looks like a professional finish.

Again, if you are afraid of invasion of insects, stack them in duplic