 They were primarily intended for television news filming and were quite popular with local and national news agencies before the advent of portable videotape Electronic News Gathering, (ENG) formats, as well as documentary and drama production.They featured a compact magnesium alloy body, a crystal locked drive system, interchangeable lenses, and a magnetic audio system with a built in mixer that recorded onto special pre-striped (and now discontinued) 16mm single perf magnetic sound film.It accepted both Mitchell and Cinema Products 400 foot film magazines.