Dry Battery Type Thin Needle Knot Slim II YH-720 (uses 2 AAA batteries).For thin yarns from 0.1 to 6!Set Harris and needle and switch on!You can easily tie the inner knot.Thin type with a thickness of about 24 mm.[Battery life] About 500 knots can be knotted (alkaline).[Compatible needles] Ise Nun 1-15, Sleeves 2-12, etc.[Compatible thread] 0.1 to 6 (nylon thread, fluorocarbon thread)