TOPCON OS-101 Specification Angle measurement accuracy: 1 arcsecond (1") Telescope magnification: 30x Objective lens diameter: 45 mm Maximum range with prism: up to 4,000 meters Maximum range without prism: up to 500 meters under suitable conditions Distance measurement accuracy with prism: ±(2 mm + 2 ppm) Distance measurement accuracy without prism: ±(3 mm + 2 ppm) within the range of 0.3–200 m Precise measurement time: approximately 0.9 seconds Fast measurement time: approximately 0.7 seconds Tracking time: approximately 0.3 seconds Dual-axis tilt compensation Display: Color touchscreen Internal memory: approximately 500 MB Connectivity: Bluetooth, USB, RS-232C Battery: Rechargeable lithium Weight with battery and base: approximately 5.7 kg Dust and water resistance: IP65