This really handy, strong, 10in x 4ft shelf can hold a seed tray placed lengthways. Use it for valuable extra growing space or above a staging to keep everything you need within easy reach. The shelves require a gap at the end as they fix to the intermediate glazing bars. For example, a 6ft wide greenhouse would only fit one 4ft slatted shelf. Whereas, a 10ft wide greenhouse could fit a 6ft shelf or two 4ft shelves.