Package quantity: This package includes 3 sewing machine bobbin cases and 15 metal sewing machine bobbins, providing sufficient quantity for long-term use and replacements. Applicable occasions: The bobbin case is designed as a replacement part for sewing machines with front-loading bobbin systems and can also be used as a spare. Featuring a polished and smooth surface, the case helps prevent scratches and ensures smooth performance during sewing, embroidery, and crafting tasks. Functional bobbins: These metal bobbins support efficient sewing operations, including garment repair, handcrafting, and patching. They help reduce thread tangling and unraveling when starting and stopping the machine. Size details: Each bobbin case measures approximately 0.91 inches in diameter, and each bobbin measures approximately 0.83 inches in diameter. These dimensions are compatible with a wide range of sewing machines, including models from Singer and other major brands. Durable construction: The bobbin cases and bobbins are made of stainless steel, offering rust resistance and durability. They are sturdy and resistant to breakage or deformation. Specifications: Material: Iron Color: Silver Bobbin size (Diameter x Height): 21 x 12 mm / 0.83 x 0.47 inches Bobbin case size (Diameter x Height): 23 x 15 mm / 0.91 x 0.59 inches Center hole diameter: 0.6 cm / 0.24 inches Package includes: - 15 x Sewing bobbins - 3 x Sewing bobbin cases Note: Slight variations may occur due to manual measurement. Color may vary slightly depending on monitor display.