Greenhouse autovent suitable for opening top hung aluminium or timber framed vents measuring up to 3ft x 2ft (900m x 600m).
The extra springs on this autovent give a closing force of approx 1.8kg (4lbs) and can be set to start opening at approx 55F (12o). Can also be fitted to roof vents in exposed positions to increase resistance to wind flutter. Also supplied epoxy powder coated white or brown.