Alton | Thermofor Roof Vent Opener Piston Replacement Coconut peat block this design allows for deep

this design allows for deep rooted plants and perennials

Its understated and timeless look will compliment your backyard

or small vegetable plants

4mm tempered glass roof and wall panels

Alton | Thermofor Roof Vent Opener Piston Replacement Coconut peat block this design allows for deepThe Thermofor Long Piston Replacement is a direct replacement cylinder designed for Thermofor automatic roof vent openers used in Alton greenhouses. If your current opener is no longer responding properly to temperature changes, replacing the piston is a simple way to restore reliable, automatic ventilation. This heat sensitive cylinder contains a wax core that expands as temperatures rise and contracts as they cool, driving the vent to open and close