Features: Our external spring calipers deliver precise measurements with high strength carbon steel and copper construction, ensuring stability and durability for accurate lathe measuring tools. Featuring flexible spring adjustment mechanism for wide measurement ranges and wear resistant materials, this precisions caliper eliminates the need for frequent tool changes. for technicians and engineers in industrial setting who require tool for daily precisions tasks and long use. for lathe machining and multiple task processing scenarios where quick adaptability to various workpiece sizes enhances efficiency. with ergonomic handle for comfortable grip and moderate weight for easy portability, reducing fatigue during extended operations. Specifications: Materials: Carbon steel and copper Size: 150mm, 200mm, 250mm(optional) Package Includes: 1PC External Spring Caliper note: Please allow 0-1cm error due to manual measurement. make sure you not mind before bid. Due to the differences between different monitors, the Pictures may not reflect the actual of the item.