... for Surveying ModelDT02DT05TelescopeImageErectErectObjective Lens Aperture45mm45mmMagnification30×30×Field of View1° 30'1° 30'Stadia Ratio100100Stadia Constant00Shortest Sighting Distance1. ... without all the extras you don't.· 30 second horizontal and vertical angle readout· An ... moved, Auto power off options of none, 20 minute or 30 minute· Optical plummet· Water resistant, sealed construction· ...