1VERSATILE USE: The long bar prism is capable of achieving accurate measurements for tunnels, mines, and other various applications, making it suitable for a wide range of measurement instruments. 2MULTI FUNCTIONALITY: This prism supports object measurements, deformations, and displacements, catering to different types of total stations. 3WIDE APPLICATION: L bar prism can be easily installed in tunnels, bridges, dams, buildings, structures, or any other fixed location or object. 4MINIATURE DESIGN: The prism is compact, portable, user friendly, and lightweight, making it easy to operate and transport in different scenes. 5ACCURATE MEASUREMENT: With a prism glass diameter of 24mm and a constant 25mm accuracy, it offers a measurement range of up to 800 meters, delivering accurate and efficient results.