Spectra Precision DET-2 Digital Electronic Theodolite,Spectra,DET-2" /> 2 second accuracy and vertical axis compensation, user selectable display resolution of 1-second or 5-seconds. Dual, backlit displays and controls, very large LCD characters are easy to see Large suite of parameter settings, includes programmable settings for horizontal angles resolution and beep, vertical degrees or percentage automatic shutoff to save battery life, zenith angle and the vertical axis compensation on or off Built in reticule illuminator and IP-54 rating low light, water and dust resistant Rechargeable kit and backup alkaline pack included, long battery life of 36 hours, backup pack runs on four standard AA batteries