Clamp device for attaching an extension to a section tube of a driver protection roof

The device (10) has a holding pin (17) for holding a disk (20) and a tarpaulin roof at a front profile pipe (3a), a lateral profile pipe(3b) and a rear profile pipe (3c) that comprises a profile cross section with two profile walls. The holding pin is integrally formed at the device and provided with a contact surface (18) for the attachment part, where the contact surface is arranged parallel to a contact surface of the profile pipe in a mounted condition of the device. The disk and the roof are arranged in a gap between the contact surfaces.