A vehicle occupant restraint device having a knee airbag deployable between an instrument panel and the legs of a vehicle occupant and including an airbag sheath and at least one exhaust orifice formed therein. The vehicle occupant restraint device further has features for qualifying the build of the vehicle occupant, an activating unit for selectively releasing the exhaust orifice and a control which actuates the activating unit depending on the qualification of the build of the vehicle occupant.