I do not recall where or of whom I bought this small film cutter, as it came into my collection some 15 yrs ago (or so). Built from acrylic plate, 4mm thick, where a single piece of regular razor blade is held by two screws. The material inside, ensuring the friction needed for holding the blade fixed is a thick foam, not perishable by the look of it. However, dirt can get on it, so one has to pay attention.
It cuts a very neat and straight strip of 9.2mm (not 9.4 or 9.5mm, mind), out of a stock of 16mm film negative. As long as you do not push too hard on the upper plate, you should be all right. Be sure to dust the cutter very well prior to its use.
Keep it away from humidity, as the blades can (and will) rust, stainless as they are advertised to be, and because of the gloss thick black paper lining the upper side (upon which the film slides) may get humid and under the pressure of the film drag, may create problems.
I use this cutter mainly for Fuji SHR 16mm negative, which I shoot when too sunny, sand beaches or in brilliant snow landscapes. As this film is rated 6-20 ASA, it is a very well suited film for such photographs. Kodak 16mm stock (BW) is also one of the films that slit well and have very good results in Minox cameras.