A Rollei projector or viewer — not a camera, but a projection/viewing device.
The Rollei VB Model 2 appears to be a Rollei slide viewer or projection device rather than a camera or lens. Rollei produced a range of photographic accessories and viewing equipment alongside their cameras and lenses. The VB designation likely refers to a specific viewer model in their product range.
As a viewing or projection device, this does not produce photographs — it displays slides or transparencies for viewing. Rollei's viewers were known for good optical quality in the viewing optic, providing a magnified view of 35mm or medium format slides. Build quality reflects Rollei's German engineering standards.
No camera mount — this is a standalone accessory device. Weight and dimensions vary by specific configuration. Build quality is solid German engineering. The device is battery-powered or mains-powered depending on the version. It accepts standard 35mm slides or other format transparencies depending on the model.
Occasionally appears on used camera markets. Not of interest to photographers as a photographic tool — it is a viewing accessory. Only relevant to slide film enthusiasts who still project or view transparencies. The decline of slide film has reduced demand for these devices significantly.