Features 1、QUALITY GLASS: Mini prism optical glass is highly machined with high accuracy, which greatly improve the measurement results, you can use with confidence 2、EASY INSTALLATION: The total station prism is light in weight, small in size, and can be installed in a few minutes, which is very convenient 3、EXCELLENT DURABILITY: The lens of the mini prism is completely covered by a rugged ABS plastic housing for excellent wear resistance and long term durability 4、CLEAR REFLECTION: The constant diameter of micro measuring prism is -25mm, and the effective diameter is 25.4mm, which can ensure the reflected image clear 5、SCOPE OF APPLICATION: Copper coated mini prism is suitable for testing in tunnels, subways, mines, highways, etc., which is suitable for measuring instruments. Widely used in railway, dam, steep slope and other industries Specification Item Type: Mini Prism Material: K9 glass and ABS Constant: -25mm Effective Diameter: Approx. 25.4mm / 1in Application: Widely used in tunnel, subway, mine, highway and other inspections, suitable for other measuring instruments Use: Widely used in industries such as subway, railway, tunnel, dam, steep slope, etc. Package List 1 x Mini Prism