Abstract: A pass-through structure for enabling objects to be transferred through a dividing wall from one area to another is disclosed wherein an outer drum is provided with opposed openings, one on each side of the dividing wall, and an inner drum provided with one opening is rotatably mounted within the outer drum so that, when the opening in the inner drum is aligned with an opening in the outer drum, objects may be placed therein and the inner drum rotated so that the opening therein comes into alignment with the opening in the outer drum whereby the objects therein may be removed. One or both of the drums may be lead-lined when X-ray film cassettes are the objects being transferred. Latch means are provided to lock the inner drum in at least one of its rotated positions.