I have 2 Corning Bake-A-Round bread tubes I use as cool tubes. They mate perfectly with 4" flexible duct and the crimped ends of rigid duct.
I wouldn't pay more than $15 shipped for one. Feebay is littered with them, but some sellers are greedy.
Like Disco said, you can use them passively to provide a standoff between your bulb and plant, or actively with air moving through them.
I wouldn't pay more than $15 shipped for one. Feebay is littered with them, but some sellers are greedy.
Like Disco said, you can use them passively to provide a standoff between your bulb and plant, or actively with air moving through them.