This is a 2-piece movement tray, laser cut from MDF. The 2 halves are not glued, allowing you to make any required modifications before gluing. PDA or super glue is recommended to glue the two halves.
The base piece is 3mm tall for rigidity, the top layer is 2mm, but can be upgraded to 3mm.
Each slot comfortably fits a 20mm square base, which is a standard size for games like Kings of War and classic Warhammer. These also make handy holders for your models to store, carry or paint.