Sokkia 0 mm/-30 mm Polycarbonate Prism System Designed for optimum performance with Sokkia and all EDM'S, the Polycarbonate Prisms are an excellent choice for use with any brand of electronic distance measuring equipment. 0 mm/-30 mm prisms offer the same distance performance with Sokkia products as Advanced Prism, but at a lower cost. Prisms are available in single and Single w Target.
With the newer EDM'S, I do not think that triple prism assemblies are required any longer.