describe This electronic ruler is equivalent to 9.9m steel ruler + 99m rangefinder + compass, suitable for straight line measurement, arc measurement, arbitrary curve measurement, irregular surface measurement and cylindrical diameter measurement in daily life and work. feature: Small and portable: 1.5cm thin body, 5.3cm surface diameter, 30g weight, convenient and practical. Premium material: This product is made of high quality 6063 aluminum alloy, high rdness plexiglass and ABS material. With compression, scratch resistance, impact resistance, more durable and longer service life. High-definition LCD display definition: display the measurement results more clearly. Ultra-low-power semiconductor microprocessors: more accurate measurement and longer service life. 99 meters long-distance measurement: millimeter accuracy, more convenient and more accurate. 10 groups of historical records: easy data query. Additional features: fast sound measurement and breathing light measurement and switching units (cm/inch). Wide range of applications: suitable for linear measurement, arc measurement, arbitrary curve measurement, irregular surface measurement and cylindrical diameter measurement in daily life and work. Size: 53*15 (millimeter) Package includes: 1 * rangefinder