Chinese-made Butterfly sewing machine (Vietnam)
This one is powered with an electrical motor.
The Butterfly is a copy of the famous Singer. There are different models of Butterfly, called: JA1-1, JA2-1, JA2-2. I'm not 100% sure which one this is, but I think it's the JA1-1.
The Butterfly are made by the Jinyun Shenma sewing machinery factory (www.shenmasewing.com).