Give your tiniest of plantings and cuttings a snug, secure start with the Hydrofarm 55-cell tray insert. Made to fit all standard 10"x 20" growing trays, this tray insert holds a total of 55 peat or coco pellets. These hydroponic staples slip right into the round holes in each section of the tray and provide the housing for your plants' roots to begin to grow. Use all of the cells at once or, if preferred, section off parts of the tray for your growing preferences.