This Medium Shade Cover is for the medium WallHugger VegTrug. The cover is perfectly designed to help your crops as it reduces the tempature of the soil. It's also UV-stabalized with the material - polyethylene material and is fade resistant to the sun. Be warned the easy fill opening system when combined with VegTrug water reservior (sold separately). This cover does the same amazing job as the others what acts as a barrier to exclude insect pests and birds. While it does this, its material is designed for accurate ventilation.