6 Compartment Shop Tray is a Horotec Swiss product. These stackable shop trays have 2 raised posts which fit into the tray above. This allows the user the ability to stack multiple trays securely. In addition, you can purchase clear lids that fit tight, and locking keys for multiple tray heights, to help reduce dust and dirt contamination, and to make storing jobs in a safe spot easy. These trays measure 237 x 105 x 17 mm (9 3/8' x 4 1/8" x 11/16").