99 meters ultra-long distance measurement with millimeter precision and 0.5% accuracy, supports stepless adjustment for enhanced convenience and includes a power amplifier for improved performance; ideal for straight line, arc, arbitrary curve, irregular surface, and cylindrical diameter measurements in daily use and professional applications. Long battery life: equipped with a built-in 200mAh low internal resistance lithium polymer battery, providing up to 200 days of standby time on a full charge; 5 minutes of charging provides up to 2 hours of operation. Constructed from high-quality aluminum alloy, high-hardness plexiglass, and ABS materials, offering resistance to compression, scratches, and impacts for increased durability and extended service life; slim design for easy portability. Wide range of applications: suitable for straight line, arc, arbitrary curve, concave and convex surface, and cylindrical diameter measurements.