This is the lower connector / drive connector for some Panasonic bread makers.
Suits:
Panasonic SD-2501
Panasonic SD-253
Panasonic SD-BT2P
Panasonic Bread Bakery SD200
Panasonic Bread Bakery SD250
Panasonic Bread Bakery SD2501
Panasonic Bread Bakery SD251
Panasonic Bread Bakery SD253
Panasonic Bread Bakery SD257