Abstract: An adjuster device for a deflector fitting of a vehicle occupant restraint system is provided, which comprises a rail adapted for vehicle-fixed mounting. The rail is provided with latching openings and comprises a bottom part and two side parts. The adjuster device further comprises a sled shiftable in the rail and adapted for being coupled to a vehicle seat. The sled is provided with a fitting part for the deflector fitting and at least one latching part which is able to cooperate with the latching openings to block the sled against a downwards displacement in the rail. The latching part is translatable from a normal rest position, in which it does not engage a latching opening, into a locking position in which it engages at least one of the latching openings, by means of a force acting downwards on the fitting part relative to the rail.