Probably manufactured for Toshiba but not branded
These come from days of old when CD readers used in CD ROM drives did not use the tray system but instead the media was placed in one of these caddies and the caddy then inserted into the drive unit.
This style of loading was used on a wide range of IT external devices mainly, Compaq and HP used them on their system but there were others. I had some CD ROM drives here that used these, Digital RRD42's but there are others using this caddy system.
Single Media (CD) Caddy
Made In Japan (stamped into the case)
The top clear lid opens when gentle pressure is applied to the rear side tabs. Open up the caddy, load the media inside and then close the lid. Insert into the external device and you are in business.
Colour is a mustard yellow - that is the normal colour, the plastic has not be discoloured due to age.
Stored and supplied in sealed plastic to maintain a dirt/dust free environment.