BAYLISS XL Autovent - full retail package Brand new stock available for immediate despatch. Offered with a manufacturer backed full 2 year guarantee. Opens greenhouse roof vents as the temperature rises, automaticaly closes as temperature drops. Automatic Greenhouse Window Opener, Simple, Strong & Easy to Fit. Made Entirely in the UK Easy to fit - Screws into wood and clamps onto aluminium greenhouses without the need for drilling. (Full fitting instructions supplied) Easy to set - one simple adjustment Solar powered - Non electric Strong build Loses no headroom Anodised aluminium construction - All parts corrosion resistant Spring controlled - Resists wind damage when opening and closing Quality assurance - All parts guaranteed for 2 years Suitable for opening hinged vents up to around 2ft square (600mm) of normal construction.