Z-GPR121 Circular Survey Prism System With Target These prisms are manufactured from high-quality optical glass which is worked to strict specifications. All reflective surfaces are provided with a resistant coating so that the reflectivity is not adversely affected by dirt or condensation. The absolute prism constant is -34.4mm or 0.0mm.
The GPR121 Professional version is manufactured from quality metal components, for accuracy and long life.
Specifications:
• Circular
• Diameter: 62mm
• Copper coated
• Centering Accuracy: 1.0mm
• Single-Tilt Assembly
• Constant: 0mm
• Available Target Colors: Yellow/Blk
• Black, Metal Holder
• Range: 11,500 ft (3500 m)
Audited Supplier 
){kind=link}