ZY987T-4DA Zoyer EX series  4-thread cylinder bed top and bottom feed overlock sewing machine
The series come with a newly developed feed mechanism that moves the top and bottom feeds separately with the combination of feed's increased differential feed ratio and improved feeding capacity, the machine is able not only to prevent uneven material feed, but also to easily finish difficult processes, such as sewing different types of materials together, ruffling and piping.