Simplicity Sidewinder Portable Bobbin Winder. With the touch of a button quickly and easily fill bobbins without having to un-thread and re-thread your sewing machine. The compact size means it fits anywhere making it great for toting to class! The SideWinder is a free-standing machine, comes with a UL-approved AC power cord/adapter (included) or runs on 2 AA batteries (not included). Accommodates all bobbins (except Viking) that have a standard round center hole and includes instructions for use. The Sidewinder features a convenient flip top, is white and measures only 3x5-1/4x3-1/2in. Imported.