Geomaster/China manufactures professional Optical Collimator Systems for Automatic Levels, Theodolites, Total Stations.... Optical Collimator System OCS-3AOptical Collimator System OCS- ... 3A is specially designed for checking Automatic Levels, Optical/ Electronic Theodolites, Total Stations and other Optical Levels.Model OCS-3AFocal Length420mmEffective ...