Grundig C100L

Philips wasn't the only one to prepare the miniaturization of tape recorders - and much before miniaturization was to mean "electronics" only, it meant making things smaller, easier to handle and, thus, cheaper.

So Grundig launched the DC International cassette: "self-threading" available in 2x 45 or 2x 90 minutes and run at 5,08cm per second, allowing a 40Hz to 10Khz frequency response.

Pre-recorded tapes were available only in 45 minutes flavor, albeit in "full-track" while recordable DC split the tape width in two for doppel recording time - as for tape speed, Grundig was here preceding Philips :-)

TELDEC, aka TELefunken + DECca, were at the DC International standard with Grundig.
However, DC failed - according to the lore, it was because Sony, already a major force in the industry, chose to support the Philips format...

Anyway, as often, the competing formats were pretty similar and both were then strictly monophonic, too - 1000ZXL s and TC-K777 s still were a good 15 years ahead in the (un)forseeable future.