Unlike the later consumer-marketed 8-track cartridge developed later in 1964 by Bill Lear which had the pinch roller integrated in the cartridge, the Fidelipac cartridge had a hole in the right-hand bottom front corner of the cartridge, where the pinch roller, built into the player instead, would swing up into place to support the tape up against the capstan.
Founded in 1959 in Silver Spring, Maryland, BE initially manufactured only endless loop cartridge "cart" machines for audio.