This negative slide is all you need to enlarge your 35mm, 645 or 6x6 negatives inside your 4x5 Pinsta camera. Simply separate the two parts and place your negative inbetween the two panels of acrylic. The markings on the light baffle (which is already included with every camera) is then used as a template to position the negative inside the slide. The negaitve slide is then positioned inside your camera body inbetween the pinhole and the photographic paper to make an enlargement.