Seat belt for a motor vehicle

The seat belt has a belt guide (10) mounted between the wind-up shaft (15) and the lap belt so that in the event of a crash it moves in the longitudinal direction of the vehicle to prevent damage to the belt. The belt guide can be fixed on the housing of the automatic mechanism. The guide has a slit opening (12) whose cross-section matches that of the belt part passing through same to form the lap belt