Botanicare? 2 ft x 4 ft Rack Tray is designed to fit standard (48 in L x 18 in D x 69 in H) chrome wire shelving. Utilizing bakers’ racks for vertical propagation allows you to increase your production by more than 300% without sacrificing additional square footage. The 2 ft x 4 ft rack is perfect for large-scale microgreen or commercial propagators looking to maximize their production. Specifically designed features allow this tray to sit flat on shelving with a trough that hangs slightly over the edge. The trough reduces standing water. This rack tray will fit four 10 x 20 in propagation trays.