Singer Metal Bobbins, 4-Pack: * Class 66 * High quality * Can be used on the following Singer models: * 66 * 99 * 101 * 185 * 192 * 201 * 247 * 288 * 327 * 328 * 329 * 401 * 403 * 404 * 413 * 416 * 418 * 457 * 476 * 477 * 478 * 500 * 717 * 719 * 814 * 834 * Can be used on the following SR series: * 6100 * 6500 * 7100 * Other drop-in bobbin machines