La Belle Commpak 16mm cartridge with magnetic sound
 

This is an odd duck. Before VHS this is what they used.

Has an 'Auto 8 Mate' for magnetic sound.

https://filmarchivedanieldteolijrarc...agnetic-sound/

A new one on me! That looks like mid-70's. Very interesting how they piggybacked on an 8-track. Not the worst idea I've ever seen. Butler, as listed on the tape, makes grain silos & that sort of thing. I guess this would have been a fairly compact unit that a salesman could carry around in his car and how to prospective clients. I had an old filmstrip projector/phonograph combo with a BF Goodrich filmstrip still in it but the record missing. I also had a Bell+Howell portable table-top projector with a built-in screen for use by salesman. All of those would have been a lot cheaper than a VCR & TV in that era.

Wow, never heard of that format...The maker is practically in my backyard.

Are they still in business?

These units were aimed at corporate Audio-Visual applications. And training applications and product demonstrations.