1、360 DEGREE PRISM: Designed with 6 separate prisms connected together, allows the measurement beam to be reflected from any angle. 2、REFLECTIVE EFFECT: Copper or silver plated film enhances the prism reflective ability, clear and bright, improving measurement accuracy. 3、SPECIFICATIONS: The prism has a constant of +21mm and an effective diameter of 24mm, which has a wide range of applications. 4、EXCELLENT GLASS: This universal prism lens is made of excellent K9 glass, which has high transmittance, making measurement easier. 5、WIDE APPLICATION: Widely used in tunnels, railways, dams, mines, highways, steep slopes, and other detection, simple and practical. 1 x Universal Prism1 x Storage Bag Item Type: 360 Degree PrismMaterial: K9 Glass, ABSConstant: + 23.1mmEffective Diameter: Approx. 25.4mm / 1inUse: Widely used in subway, railway, tunnel, dam, steep slope, mine, highway and other detection