What Will You Receive: You will get 25 pieces metal spools enough for your daily sewing needs. The bobbins are compatible with most standard sewing machines compatible with Brother Singer Janome etc. You can also use them for hand sewing or embroidery projects. High Quality Material: These sewing machine metal spools are made of sturdy metal which is durable and rust-resistant. The metal is smooth and shiny preventing the thread from snagging or fraying. You can use them to store different colors of threads or replace the broken ones. Special Performance and Design: These sewing machine bobbins have a unique bobbin winder design which allows you to wind the thread quickly and evenly. The bobbin winder also has a locking mechanism which prevents the thread from slipping off or unwinding. The bobbins have a standard size of 2cm in diameter and 1cm in height which fits most sewing machines and bobbin cases. Easy to Use: The bobbins are easy to install and remove from your sewing machine or bobbin case. You just need to insert the bobbin into the bobbin holder thread it through the tension spring and then pull it out when you are done. You can also use the included storage box to organize and store your bobbins neatly and conveniently.