Features Using Good Glass: Having been through excellent workmanship, the optical glass comes with high accuracy to largely improve the measurement. Clear Reflection: Designed to have ‑25mm constant and 25.4mm effective diameter, the mini surveying prism ensures clear image in reflection. Great Durability: The lens is fully covered by sturdy ABS plastic housing, which has great durability against wearing and long term use. Wider in Utility: Suits perfectly for Leica and other measuring instrument, the L bar prism can be widely applied to a variety of testing. Easy Installation: Light in weight and compact in size as well, the total station prism is very convenient to install in several minutes. Specification: Item Type: Mini Surveying Prism Material: Optical Glass, ABS Constant: -25mm Effective Diameter: Approx. 25.4mm / 1in Application: For the testing of tunnels, subways, mines, highways, etc. Suitable for Leica and other measuring instruments. Use: Widely used in various industries such as subways, railways, tunnels, dams, steep slopes, etc.  Package List:1 x Mini Surveying Prism Package List 1 x Mini Surveying Prism