Duct Flange 

The Duct Flange works great for venting any type of enclosed growing tents. 

This kit consists of a single duct flange that allows you to mount ducting to vent the heat of your growlight bulb.

Pull the heat outdoors using an exhaust fan during warm weather. If you live in a 4-season climate, exhaust your bulb heat indoors to cut heating costs (it's odor-free!).

Duct flanges are made from thick formed sheet metal and painted on all sides. They attach to a matching fastener ring using screws.

Comes complete with:

1 flange
1 fastener ring
6 screws

Choose a "set of 2" if you need a double flange arrangement.