Alton | Thermofor Roof Vent Opener Piston Replacement Partyhouse 9% harmful UV radiation that

9% harmful UV radiation that won't yellow or become brittle over time

Does this greenhouse include automatic vent openers

and protective wire guards ensure reliable

for additional strength and rafter stiffness

Floor-standing milkhouse-style heater

Alton | Thermofor Roof Vent Opener Piston Replacement Partyhouse 9% harmful UV radiation thatThe 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