Features Better Design: Comes with 64mm effective diameter and 0/-30mm prism constant, the single tilt prism ensures great accuracy. Clear Imaging: The k9 glass accessory enables high clarity in the imaging, which will largely simplify measurement and work. Wider Utility: Works perfectly with total station, the prism can be widely applied to the survey of tunnel, mine and so on. Durable Using: Thanks to the ABS casing, the single tilt prism with a sturdy structure is durable with wearing and long use. Easy to Install: Light in weight and compact in size as well, the easy installation can be quickly completed within minutes. Specification: Item Type: Single Tilt Prism Material: k9 glass, ABS. Effective Diameter: Approx. 64mm / 2.52in Constant: 0mm, -30mm Application: For the detection of tunnels, mines, highways, etc. Suitable for various measuring instruments. It is widely used in various industries such as railway, tunnel, dam, steep slope, etc.  Package List:1 x Single Tilt Prism1 x Cover1 x Storage Bag Package List 1 x Single Tilt Prism 1 x Cover 1 x Storage Bag