Fukui Dark Sea Stackable Trays have been used, tested, and improved for close to ten years. Made of polyethylene and bearing a square shape with flattened corners (almost a hexagon), Dark Sea Trays offer pass-through for ropes on all four corners for deployment - or a suspender kit can be purchased. Suspender kits include the bottom fitting and aluminum plate as well as the top fitting and S.S. eye hook. Optimum water flow and nutrient accessibility is obtained by large mesh on all four sides of the trays. Smaller mesh inserts are available for the bottom when using smaller seed.