Feature:1. MEASURING PRISM: This is a measuring prism with an ABS protective shell, a basic circular prism reflector, and a bracket, easy to use.2. EFFECTIVE D64MM: The effective diameter of this measuring prism is 64 mm, and the offset is 0mm or 30mm, standard and practical.3. OPTICAL GLASS: Optical glass lens is carefully polished, with a uniform and delicate coating on the surface to ensure observation performance.4. HIGH ACCURACY: Our surveying triple prism can ensure the accuracy of measurement, you can use it with confidence.5. WIDE APPLICATION: The total station surveying prism can be used for detection of tunnels, subways, mines, highways, etc.Specification:Item Type: Triple PrismMaterial: Optical Glass, ABSEffective Diameter: Approx. 64mm/2.5inConstant: 0mm/-30mmApplication: Detection of tunnels, subways, mines, highways, etc. Suitable for measuring instruments such as for TrimbleUse: Widely used in various industries such as subways, railway, tunnel, dam, steep slope, etc..Package List:1 x Triple Prism3 x Lid1 x Storage Bag