The bobbin case is the part of the sewing machine that holds the bobbin and maintains the tension of the bobbin thread. Tension can be adjusted using the screw located on the side of the bobbin case. It is recommended to use only bobbins specifically designed for this bobbin case to ensure proper performance and to avoid skipped es or potential damage to the sewing machine. Compatible with Singer sewing machine models: 1022, 1100, 1247, 1247N, 1250HD, 1263, 1263N, 1280, 1280N, 1288, 1288N, 1482, 1485, 1486, 1488, 1490, 1492, 1730, 1802, 1803, 1812, 1852, 1853, 1862, 1872, 1873, 2102, 2105, 2106, 2108, 2110, 2112, 2114, 2118, 2210, 2302, 2303, 2304, 2315, 2330, 2404, 2430, 2440, 247, 247AP, 2502, 2503, 2504, 2515, 2517, 2530, 2543, 257, 2712, 2718, 2722, 2724, 2730, 2732, 2808, 2818, 288, 2950, 30920, 3100, 3101, 3102, 3103, 3105, 3130, 3140, 3270, 3314, 3317, 3343, 353, 354, 358, 4325, 4517, 4522, 4525, 4526, 4528, 4530, 4538, 4552, 4562, 4572, 4610, 4620, 4622, 4624, 4814, 4817, 4818, 4820, 4822, 4824, 4825, 4826, 4828, 4830, 4832, 495, 500K, 5017, 502, 5028, 5040, 5050, 507, 509, 510, 513, 514, 5160, 518, 522, 527, 530, 533, 534, 538, 5405, 5417, 543, 5430, 560, 5605, 5610, 5705, 5710, 57815, 57815C, 57817, 57820, 57820C, 57825, 5802, 5805, 5806, 5808, 5810, 5812, 5814, 5816, 5817, 5818, 5820, 5825, 5830, 5830C, 5838, 5910, 5932, 6011, 6012, 6021, 6038, 6100, 6102, 6104, 6105, 6106, 6110, 6112, 6114, 6115, 6116, 6120, 6122, 6124, 6125, 6130, 6136, 6146, 6152, 6156, 6174, 6184, 6201, 6202, 6211, 6212, 6214, 6215, 6217, 6221, 6233, 6500, 6513, 6522, 6528, 6533, 6543, 6544, 6548, 6606, 6610, 6620, 6700 Series, 6705, 7004, 7015, 7021, 7025, 7028, 7029, 7033, 7035, 7100, 7101, 7102, 7104, 7105, 7106, 7108, 7110, 7136, 714, 717 School, 7174, 7184, 719, 7211, 7212, 724, 734, 774, 776, 800, 8002, 8007, 8019, 8100, 8200, 8220, 827, 830, 833, 834, 844, 8500, 8502, 8505, 8518, 8600, 8602, 8605, 8606, 8610, 8614, 8618, 8734, 8774, 8834, 9005, 9008, 9010, 9015, 9018, 9020, 9022, 9027, 9030, 9032, 9034, 9044, 9110, 9130, 9134, 9210, 93220, 9323, 93234, 9334, 935U, 9408, 9410, 9416, 9420, 9423, 9430, 9432, 9440, 9444, 9500, 9502, 9505, 9518, 9600, 9602, 9605, 9606, 9608, 9610, 9612, 9614, 9618, 964, 966, 968, 972, 974, 9802, 9803, 9805, 9806, 9808, 9810, 9812, 9814, 9816, 9818, 9824, 9828, 9836, 9858, 9936, CG500, CG550, CG590, CM17, CP17, DL17, DX14C, FM17, FM19, FM22, HD102, HD105, HD110 Alternate Part Numbers: 421326-901, 421325-000, 421325, 421325-001, 421325003, 421325-002, 421325001, 421325-001