a rollover protection device includes a cassette housing which guides an extendable rollover bar . the cassette housing includes guidances for the rollover bar . the rollover bar is a single shell or multi - shell form part made of fibre reinforced plastic and has shell edge regions which at least partially extend parallel to the extension direction . the cassette housing is a hollow profile made from high strength material and is closed around the rollover bar and the guidance . the guidance is a plastic form part engaging at a shell edge region , is secured within the hollow profile and protrudes from the hollow profile at least downwards .