Pack of 30 Schmetz Industrial Overlock Sewing Machine Needles. Needle System : B-27 Equivalent needle system numbers : 1886, 88X1, B27, DCX1, DCX27, RIM27, RMX27, MY1023, SY6120, UY191GS These are round shank needles for industrial overlock machines. Will not work on home portable sergers. Schmetz B-27 needles are available in following sizes. Please select your size. Singer Size 9 (Metric Size 65) Singer Size 10 (Metric Size 70) Singer Size 11 (Metric Size 75) Singer Size 12 (Metric Size 80) Singer Size 14 (Metric Size 90) Singer Size 16 (Metric Size 100) Singer Size 18 (Metric Size 110) Singer Size 19 (Metric Size 120) Singer Size 20 (Metric Size 125) Singer Size 21 (Metric Size 130) Singer Size 22 (Metric Size 140) Lower size numbers are narrower or thinner needles used for lighter materials. Higher size numbers indicate a needle of thicker diameter, used for heavier materials. Match your needle system to your machine, then the size of the needle to the product you are sewing. These are high quality round shank needles used on many industrial overlock machines including : Babylock : BL3-318, BL3-407, BL3-408, BL3-416, BL3-418, BL3-426, BL3200, SL600, SL660, SL700, SL800 Brother : B511, B531, B551, B561, B571, B611, B621, B641, B651, B661, B671, B672, B681, B682, B691, B692, B901, B952, B958, B959, B971, B959 Feiyue : FY737, FY747, FY757, FY2000, FY2100 Juki : MO-800 Class, MO-2400 Class, MO-2500 Class, MO-2400N Class, MO-2500N Class, MO-3300 Class, MO-3600 Class, MO-3700 Class, MO-3900 Class, MO-6700 Class, MO-6800, MOR, MOC, MOF Mauser : DC, DCP, DC-MS Pegasus : E22-730, E22L-730, E32, E32L, E52, E52L, ETB32, ETB52, ETF32, ETF52, F32, F52, L32, L52 Rimoldi : 27, 28, 29, 227, 228, 229, 230, 327, 329, 527, 627