ITEM NAME:10pcs 21mm Industrial Aluminum Bobbins For Singer Brother Sewing Machine Toolj Specification: Brand new Diameter: approx. 21mm Height: approx. 8mm Aperture: approx. 6mm Material: aluminum Machine: single needle flat car Color: silver Suitable for: This bobbin for general flat car. Computer flat car, aluminum products, anti-Lai wear, rust Bobbin computer with ramp bobbin core industrial sewing machine bobbin Package included: 10pcs x bobbins Note: Please allow minor error due to manual measurement. The colors may be a little difference for the different monitor display..Bobbin computer with ramp bobbin core industrial sewing machine bobbin. Suitable for: This bobbin for general flat car. Computer flat car, aluminum products, anti-Lai wear, rust. Machine: single needle flat car.