Encorder 400, 1960s
Rim drive. Approximately 7-3/4 inches / 20 cm long.
Based on its appearance and construction, this recorder is probably from some time during the period 1962 to 1966. But I'm just guessing, because unlike most of the other recorders here, I have no recollection of seeing this one in the catalogs I pored over as a youngster.
Here's what it looks like with its cover closed. That red thumbwheel on the right side is the volume control.