These plastic bobbins fit a wide variety of sewing machines which use the Class 15 style bobbins.  Machines which use this bobbin style include but are not limited to:

Babylock BL37, BL40, BL40A Grace, BLCP, BL137A, BL137A2 Sofia 2, BL200A Elizabeth, BL6300, BL6800, BLCC Crafters Choice, BLCC2 Crafters Choice 2, BLDC Decorators Choice, BLDC Decorators Choice 2, BLG Ellegante, BLG2 Elegante 2, BLL Ellageo, BLL2 Ellageo2, Ellure 2, BLMR, BLMY Melody, BLN Esante, BLQC Quilters Choice, BLQC2 Quilters Choice 2, BLR Ellure, BLR2 Ellure, BLSO Ellisimo, BLSR Espire, BLTP Tempo, INT Intrigue, - Brother, BC1000, BM2700AS, BM3600AS, BM2800, CE4000, CE5000PRW, CE5500, CE5500PRW, CE8080PRW, CP6500, CP7500, CS100T, CS4000, CS5055PRW, CS6000, CS6000B, CS6000I, CS6000T, CS770, CS8000, CS8002, CS8060, CS8072, CS8080, CS8120, CS8130, CS8150, CS8200, DS120, DS140, ES2000, EX660, FS20, FS40, FS40WT, GS2700, HC1850, HE120, HE240, HE420, HS1000, HS2000, HS2500, HS3000, HS9500, JS23, LB6770PRW, LB6800PRW, LS590, LS1217, LS2020, LS2125, LS2129, LS2130, LS2150, LS2160, LS2220, LS2720, LS2725, LS2820, LS2825, LS2920, LS30, LS400, LS590, LS6770, LX2500, NS20, NS30, NS40 NV500D, NV750D, NV750, NV780D, NV900D, NV950D, NV1000, NV1200, NV1250D, NV1500D, NV2500D, NV2800D, NV4000D, NV4500D, NV6000D, NV6700D, NX200, NX2000, NX250, NX400Q, NX450, NX450Q, NX570Q NX600, NX650, NX650Q, NX800, PC210, PC210PRW, PC420, PC420PRW, PE700, PE700II, PE770, PE780D, PS21, PS2250, PS2300, PS2500, PS3100, PS3700, PX100, PX150, PX200, PX300, QC1000, RS15, RS25, RS35, SB3129, SB530T, SB170, SC6600, SC9500, SE270D, SE350, SE400, SL7, SM6500, SQ9000, SQ9050, SQ9185, VQ3000, XL2120, XL2121, XL2130, XL2140, XL2150, XL2230, XL2240, XL2250, XL2600, XL2600I, XL2610, XL3500, XL3510, XL3750, XL3800, XL6040, XL6050, XL6060, XL6452, XL6552, XL6562, XM3700, XQ2700, XR31, XR33, XR46, XR52, XR52C, XR4040, XR65, XR65T, XR1300, XR3100, XR4040, XR6060, XR7700, XR9000 XR9500PRW - Outside diameter: 20mm.

Numerous other manufacturers also use this style bobbin including: Janome, New Home, Elna, Sears Kenmore, EuroPro and Singer