The machine has tructure of twin-needle and split needle bar. It's very convenient to make corner seam, acute angle seam and straight seam, and to sew two parallel lockstitch of any angle. It's suitable for decoration and corner seaming of underskirt, ladies' underwear, jean wear, overcoat, etc. JK842: fixed needle bar, small hook JK845: split needle bar, small hook JK872: fixed needle bar, large hook JK875: split needle bar, large hook