The invention relates to an apparatus which is preferably designed as a saddle stitcher. Depending on the format of a printed product, an adjustable stop acts after a stapling station. The timely takeover takes place through a paper delivery device when the printed product consisting of one or more folded sheets is output. The paper delivery device has, in its inlet area, an apparatus to receive the output printed product. The apparatus consists essentially of movable means, which can be controlled in accordance with the measured thickness of the output printed product. The apparatus preferably have pivot arms in pairs on both sides of the inlet area of the paper delivery device, each pair consisting of two pivot arms extending substantially vertically and spaced apart from each other. Each pair of pivot arms is in acting connection with a double-extending cam disc. The cam disc causes the pivot arm to stretch through rotation and simultaneously causes the distance between the paper feed rollers in acting connection with the pivot arms to change relative to each other. This depends on the corresponding measured thickness of the output printed product.