Professional Extremely Robust Ideal For Outdoor Use Designed For Outdoor Use Due To Sturdy Metal Housing With Dust And Splash Protection Ip54 Robust Design With Built In Target Collimator And Integrated Circular Vial Compensator Lock For Safe Transport Target Collimator For Rough Alignment Penta Prism Makes It Easy To Read The Circular Vial Large Focusing Knob For Easy Alignment Fast Aperture For Excellent Staff Reading High Precision 1mm/30 M Over Long Distances Endless Degree/angle Setting Using Knobs On Both Sides With Friction Braked Rotation Erect Image Technical Specifications Unit Of Measure