The Dritz Plastic Bobbin Box - Clear is a useful addition to your sewing kit. This see-through plastic case holds bobbins neatly in place while allowing you to view them at a glance. It is a lightweight box, which is capable of holding 21 regular bobbins or 42 Singer 600 series plastic bobbins at a time. A bobbin box measuring 4 x 6 x 1.25 inches is included in this pack. Bobbins can be purchased separately.