B2C is a series of foam pad capacitive keyboards from Omron. This can be see on a B2C-68E4VL-101-011 label. As the model number suggests, B2C-68E4VL-101 keyboards are 68-key. “E4” may denote that it is quad-mode encoded but this by no means certain.
Models B2C-66E4VL-406 and B2C-66E4VL-417 are noted as being for specific customers. For the remaining models, the document notes that the key layout is the same, but there are differences in the parts, thus one should check the specifications. (キーの配列は同じですがー部異なる点がありますので，製作仕様書にて確認ください。)