GRZ4 Replacement Surveying Prism for Leica robotic total station, Advanced Automatic Tracking High Precision 360 Degree Universal Total Station Prism, Equipped with a Constant and Swift Release Button Mechanism. Prism Height: 3/78 mm. The bottom is a Dia 0.47/12mm Socket. Constant: +23.1mm offset, accuracy: +/-2mm. After-sale-service: If you need a large quantity of goods, please contact me, I will give you a good price.