99 meters ultra long distance: millimeter precision, 0.5%, supports stepless adjustment, more convenient and more power amplifier; more precise. It is suitable for straight line measurement, arc measurement, arbitrary curve measurement, irregular surface measurement and cylindrical diameter measurement in daily life and work. Long Battery Life: Built-in 200mAh low internal resistance lithium polymer battery, after fully charged, can achieve long standby time up to 200 days. Charge for 5 minutes and last for 2 hours. High-quality materials: This product is made of high-quality aluminum alloy, high-hardness plexiglass and ABS materials, resistant to compression, scratches and impacts, more durable and has a longer service life. Thin body, easy to carry. Wide range of applications: it is suitable for straight line measurement, arc measurement, arbitrary curve measurement, concave surface measurement and convex, the measurement of cylindrical diameter in life