"Johnson's 40-6532 Self-Leveling Rotary Laser is designed for the Professional Tradesman who works both indoors and outdoors. This pro quality tool offers an exterior working range of 2000' (when used with a red beam laser detector/not included) at an accuracy of 1/8"" at 100'. Four rotational speeds of 150, 200, 250, 7 300 RPM allows thi...