These Diorama (Unit) Washers come in a set of 6 40mm high-quality, plastic washers. Two 40mm models to chose from! Option one: SKU PP has an interior diameter of is 41.5mm (exterior diameter is 51.5mm) Option two: SKU GW has an interior diameter of 40mm (exterior diameter is 50mm). Custom Unit Washers for use within TABLEWAR's Modular Display and Storage Tray System for use with hobby miniatures and models. These Unit Washers have been designed to give you the ultimate flexibility in arranging the TABLEWAR® Unit Tray or Diorama Tray. Mix and match them with other sized Unit Washers. Arrange them, secure the, use them. You may attach them to a plastic or a metallic surface. Your hobby miniatures and models sit within the interior of these washers.