The Bass 2 in a Hohner catalogue from April 1973:
Below is my translation of the text. I'm not sure of the accuracy of the part about the spare fuse, though.
HOHNER Bass 2The upright bass in a carrier bagA purely electronic musical instrument with transistor technologySupplied with rubber feet and a tripod, it can be played as a table instrument or on a tripod with a ball-and-socket joint (available as an accessory).The HOHNER Bass is monophonic.The tone reproduction happens over suitable amplifying equipment.Technical Data:30 piano keys of normal width from E1-a = 2½ octaves3 timbres - guitar - string - tuba - can be chosen with a key set.The decay time (percussion) is smoothly adjustable, when the switch is turned on. By pulling on the switch, playing with a continuous tone is possible.The mains switch is combined with the smoothly adjustable volume control.The instrument is supplied with:Carrier bag, connecting cable, spare fuse (0.16 A medium blow)Weight: 4,950 kgDM 590Available accessories:Tripod, ball-and-socket joint, tripod bag DM 100
Here's a picture of a Bass 2 that I found on Instagram, shown with what is apparently the carrier bag mentioned in the catalogue:
