☆●□▲□●◇●●◆●〇□★●▼☆☆▽▲ Hello, thank you for viewing the product. Immediate purchase without comment is welcome! We ship within 24 hours on weekdays. This is a grooved aluminum bobbin specifically for industrial and professional sewing machines. + Lightweight aluminum material makes thread tension easier to stabilize. + Rust-resistant, so no maintenance is required. + The groove in the shaft is a <cut type> that can be set on a thread winder. Bobbins are consumables, so replace them early if you feel any discomfort! If you want more than 20 pieces, please let us know in the comments. As this is an overseas product, there may be fine scratches or stains during the production process or shipping. The color of the actual product may differ from the image due to the settings and output environment of the device and monitor you are viewing, as well as the lighting during photography. We inspect the products before shipping, but if there is a problem with the product, please contact us before evaluation (before the transaction is completed).