The small square head type is most suitable for cylindrical sewing, making sewing operations easier. The circumference of the small square head is only 148mm. Not only can the cuffs of T-shirts and children's clothing be folded, but also short depth clothing and small cylindrical clothing can be easily completed And there are no obstacles around the small square head, and a 10mm space is designed on the right side of the needle drop point, so various devices can be installed and high-quality sewn products can be obtained. Make the advantages of small caliber upper and lower differential sewing machines more prominent. The XOT70 series, which adopts an independent feeding mechanism, has an increased differential ratio and a qualitative improvement in conveying efficiency. The effective feeding distance of the upper feeding teeth increases, the straightness of the fabric increases, and stable and perfect stitching is formed.