DRITZ-Metal Class 66 Bobbins. For 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 series 6100 6500 7100 and other drop-in bobbin machines. This package contains four bobbins measuring 6/16in top to bottom. Imported.