The basics Overlock needles have a sharp point and are suitable for all fabrics. The benefits The uses The type of system determines whether your customer needs Art. 1740 or 1741. The BLX on the package of 1740 refers to Baby Lock machines, but this needle fits other brands as well. Customers should refer to their machine manual to know whether BLX or DCX is needed. The bottom line 5 per package: two size 11/75 and three size 14/90.