This unit works well with 35mm and 6 x 4.5cm slides and negatives As another reviewer mentioned, putting a light underneath it helps to avoid film frame separations to determine exactly. My scanner accepts 35mm wide strips of 6 frames and cuts the film to the correct length perfectly. When I receive the negatives and slides from the lab they come in separate long strips in long clear glassine sleeves that protect the entire roll. The cutter is more difficult to use with foil in an envelope. But that's not what it's designed for, and that little comment is understandable. The price seems a bit high considering the design of the product. This may be because it is a specialty item with lower demand and the economics of mass production may not apply. I would have given it five stars if it wasn't for that.