1 Specialized for detecting whether the surface line of the spinning sewing machine is broken or not, and the bottom line can not be detected.
2 When not in use, you can press the locking switch without removing it from the machine, and when in use, you only need to open the locking switch, which is very convenient.
3 card slot width of 7mm and 5mm two kinds, most domestic manufacturers use 7mm wide machine.
4 must have computer support, mechanical machines can not be used.