Asimeto Plug Thread Gauge (D/E) - Metric - Right Hand - 6H - M39 x 4The Asimeto Plug Thread Gauge (D E) Metric, Right Hand, 6H, M39 x 4 is a precision go no go tool crafted for reliable internal thread verification. Designed for machinists, inspectors, and quality teams, it delivers repeatable checks that help keep every part within spec. Dual end design (D E): Two ends optimized for go no go checks on internal M39 x 4 threads with a right hand configuration. Thread size and tolerance: M39 x 4, 6H coarse metric