The invention includes a device for supplying preforms having a collar. The device comprising a file-forming slide for the preforms, and the slide comprises a fixed frame and elements for guiding the preforms. The guiding elements are mounted so as to be adjustable in terms of position on the frame so as to be adapted to different formats of preform. The frame comprises support plates that are fixed in a reference position on the frame by removable fastening means, the guiding elements being mounted so as to be adjustable on the support plates.