What you will get: The package includes 4 pieces, a sewing machine bobbin case that you can change and replace according to your own interests, or share with others. Application: the Robin box is used as a spare part for a front-loading bobbin sewing machine, and can also be used as a spare part Function: The bobbin can stop threading faster, effectively preventing threading. lower thread from loosening when the sewing operation stops and starts. Material: The bobbin case is made of stainless steel, which is durable and very practical for long-term use. Packing list: 4 * sewing machine bobbin case We only sell sewing machine bobbin case, not other items in the picture. Due to the differences between different monitors, the pictures may not reflect the actual color of the item. Due to manual measurement, please allow slight size errors.