with Added Roof-ventpre-set Holes For Pinning To The Soilcreates A Beneficial Greenhouse Environmentreuse Again & Againideal For Cauliflowers, Cabbages & Young Courgettes protection From Weather & Protection From Garden Pests.like The Glass Cloches Of The Victorian Era, This Duo Pack Of Bell Jars Is Equally Efficient In Warming Up The Soil For Earlier Harvests & Protecting Your Crops From Slugs & Other Garden Pests. It Also Encourages An Ambient Environment That Makes Use Of Optimum Sunlight For Quick & Strong Growth.these Bell-jar Cloches Are Equally Effective As Glass But Less Heavy, Less Breakable & Less Expensive. Your Bell-jar Cloches Harness The Most Light Thanks To The Rounded Bell Design That Captures To Greatest Amount Of Sun. Just Place Them Over Individual Brassicas Or Young Shrubby Plants & Fix Them Into The Soil With Pegs Through The Pre-set Holes.ideal For Placing Over Large Brassicas & Ornamental Bedding To Protect Them From A Late Frost Or Sudden Storm. In Winter, These Bell-jars Are Perfect For Offering Protection From Slugs On Winter Brassicas & Oriental Winter Salads. You Can Easily Lift Off The Bell-jars By Removing The Pegs When You Need To Water Or Feed Your Plants.useful Tip:your Plants Are Still Able To Appreciate A Healthy Air Flow Even When Covered Thanks To The Manual Roof-vents You Can Open & Close In An Instant.