No-load speed 1500rpm 1000rpm 600rpm 400rpm. Performance /Features Industrial grade, fast speed, small strength, precision gun body; suitable for pulling M3 M4 small size Industrial grade, fast speed, slightly stronger, precision gun body; suitable for pulling M4 M5 M6 three specifications Industrial grade, low number of revolutions, high strength, precision gun body; suitable for pulling M5 M6 M8 Industrial grade, low number of revolutions, high force, precision gun body; suitable for pulling M6 M8 M10.