The automatic, self-leveling Spectra PrecisionT Laser HV301 is an economical laser with exceptional versatility and visibility. Whether your job site is indoors or outdoors, the HV301 is capable of handling a wide variety of horizontal, vertical and plumb applications. Its high-visibility beam enables 90-degree simultaneous rotating and plumb/perpendicular references.Sometimes referred to as a lazer or Rotary lazer