Features: 1.The bobbins will not fall from the machaine easily, thus ensuring a more stable sewing. 2.All the bobbins have smooth edge, which makes it easier to wrap the thread without cutting it. 3.23-piece set will satisfy your needs for updating and replacing old accessories, very convenient. 4.Also, there is a threader in the set, and easier threading will largely improve your efficiency as well. 5.Comes with a storage box, very easy to store and carry. And the stainless steel bobbins are very durable. specification:Item Type: Sewing Machine Bobbin Set Product s: One Set Product Material: Stainless Steel + Plastic Function: Household, update and replace old accessories, etc. Scope of Application: Most industrial sewing machines. PackageList: 23 x Sewing Machine Bobbin 1 x Sewing Machine Bobbin Case 10 x Sewing Machine Needle 1 x Threader 1 x Storage Box