• Basic encasement for recessed installation, made of ABS plastic. • Stainless steel spigot, integrating the K90 fireproof valve, TUM certified according to DIN 18017-3. • Backdraught shutter compliant with DIN 18017-3, as certified by TUV German Institute. • Spigot nominal diameter: 80 mm. • Square frame to prevent entry of dirt and plaster. • Connection port to connect a spigot (QE-AD cod. 21118, available as accessory) able to extract air from a second room. • Possibility of drywall installation.