Exaco Trading Company Triple Box 20374 Raised Bed with Cold-Frame Unique triple-box raised bed planter, made from heat insulating and frost resistant garden elements (hollow bricks) Each section (24") comes with a removable cold frame cover (5" high) made from twin-wall polycarbonate Bricks do not leach like preservatives in wood products Bricks will outlast any other material for raised beds (wood or plastic) Unit also includes a Gardena Drip-Hose system