Take control of your sewing machine bobbins! The BobbinSaver organizer holds standard size bobbins, such as class 15 and style L. If your bobbin is ruffly the size of a nickel, it will fit this holder. Shaped like a hollowed out donut, it's made of flexible rubbery plastic that expands to hold the bobbins nice and snug. The bobbin organizer easily holds over 20 bobbins, securely. The unit measures 3/4" tall and 5 1/8" diameter.