The AV Stumpfl Magnum SK21 is a roll-up transport box designed for transporting roll-up screens with a maximum fabric width of 550 cm. It has stated internal dimensions of 260 × 330 × 600 mm and a gross and net weight of 88 kg. The product is an accessory rather than a projection screen and is identified by manufacturer article number BRV-SK21/550. No video inputs, outputs, connectors, or included accessories are specified.