Usage Tips:Package quantity: package comes with 3 pieces sewing machine bobbin cases, 15 pieces metal sewing machine bobbins, enough quantity to meet your long time use and replacements. Applicable occasions: case can be applied as a replacement part for sewing machines with front-loading bobbin systems, you can also apply it a spare case; Designed with polished and smooth surface, case will not cause scratch and can work fluently on your sewing work, embroidery work and art work Functional bobbins: these metal bobbins can help you to deal with much sewing work, handmade and patch the clothes, can stop more quickly, effectively prevent unraveling or tangling of bobbin thread when sewing operations stop and start Size details: each sewing bobbin holder case measures approx. 0.91 inch in diameter, and each bobbin measures approx. 0.83 inch in diameter, which can be applied for most sewing machines, compatible fit for , , , , , , Singer and more Durable to use: the sewing bobbin case and sewing machine bobbins are made of stainless steel, rust proof and sturdy, not easy to break or deform. Specification: Material: Iron Color:Silver Size(DiaxH): 21x12mm/0.83x0.47inch,Bobbin Cases Size(DiaxH):23x15mm/0.91x0.59inch, Hole: 0.6cm/0.24inch Package Includes: 15 Pieces Sewing Bobbins 3 Pieces Sewing Bobbins Case Note: Please allow slightly difference due to l measurement. Color may be slightly different since different monitor. Thanks!