Electronic Bobbin Winder RS-11MB Electronic Bobbin Winder unit base Part Number: RS-11MB Compatible with standard 21mm bobbins and larger ones up to 28mm in diameter. Easy to install and operate with an On/Off switch and a thread tension adjuster. Includes a thread cutter blade for added convenience. Automatically shuts off when the bobbin is full. Fits all common bobbin types, including: Type M Type L Type 15 (universal) Any bobbin with a 1/4 inch (6.4mm) centre hole.
