Item Type: Right Angle Prism_x000D_Material: Optical Glass, ABS_x000D_Color: Black_x000D_Constant: -25mm_x000D_Effective Diameter: Approx. 25.4mm / 1in_x000D_Application: For tunnels, railways, mines, highways, dams, steep slopes detection, etc. 1SPECIFICATIONS: Double sided right angle optical prism, the prism constant is -25mm, effective diameter is 25.4mm, accurate and stable. 2OPTICAL GLASS: This double side prism uses excellent optical glass, with fine cutting and polishing to ensure accurate measurement. 3GOOD REFLECTION: Excellent coating enhances the prism reflective ability, making it clear and bright, improving measurement accuracy. 4PLASTIC HOUSING: Oxidized plastic coated lens, which ensures good wear and impact resistance, greatly extending prism lens service life. 5L SHAPE STAND: The right angle prism has L shape stand for stable operation, widely used for railway, tunnel and highway detection.1 x Right Angle Prism