Needle bar and upper looper mechanisms are applied active oil supply and entirely sealed vacuum oil return system. The new system exceeds the traditional oil supply of rope type and dropping type. – Needle bar height adjustment without opening machine. – Lower looper holder fine-tune mechanism. – Chainstitch fine-tune mechanism: Open the rare cover to adjust stitch length easily. – Needle plate thread groove leads to perfect loop. – 5 cm height sewing area offers better cloth movement.