AV Stumpfl Inline-Spring Roller Strato case designed as an accessory for the Inline-Spring Roller Strato projection-screen system. The case is identified as size 9 × 8.5 cm and is supplied as a single piece. Manufacturer AV Stumpfl assigns the product article number BIS-S/SK090/R5. The item is categorized as an accessory rather than a projection screen and therefore has no projection surface, aspect ratio or surface-gain specification.