1,All alumina body make the instrument more stable and firmly. 2,the aborative designed appearance looks more beautiful. 3,The main part has excellent sealed for all kinds of field work in any weather. 4,The advanced structure supply the friction-braked rotation , and endless horizontal drive with a knob at each side, 5,Horizontal circle can be readout 1?or 1gon directly . 0.3m is the shortest focusing for measurement in confined spaces.