Round, levelable heavy-duty cassette, blind in nominal size R4 for creating an inspection opening in duct systems, raised and hollow floors. Suitable for dry or wet-maintained floors, only for smooth floor coverings. Load class 2 up to 20 kN. Cassette frame with integrated locking ladder for installing 2 device cups (2x GB2) for 4 individual installation devices with carrying ring/carrying bracket or 6 Module 45 devices.