Features Optical Glass: This L shaped prism is accurately inspected with carefully polished optical glass for more accurate and sturdy measurements. Oxidized ABS Wrapped: This L shaped prism uses oxidized ABS wrapped around the lens to resist abrasion and drop, making the prism resistant to abrasion and drop and greatly improving the life of the prism. Coated Film: This L shaped prism is coated with film to enhance the reflective ability of the prism, with full texture, clear and bright. Wide Application: This L shaped prism is widely used in many industries such as subway, railroad, tunnel, dam, steep slope and so on. Compact And Portable: This L shaped prism is small in size and light in weight, which makes it very convenient to carry around and use. Specification: Item Type: L Bar Mini Prism Material: Optical Glass, ABS Specification: Basic Type Constant: Approx. -25mm Effective Diameter: Approx. 25.4mm/1in Application Scope: Tunnel, Subway, Mine, Highway And Other Inspection, Applicable to Many Measuring Instruments Use: Widely used in subways, railroads, tunnels, dams, steep slopes and many other industries packing list: 1 xL Bar Mini Prism Package List 1 x L Bar Mini Prism