Northwest Instrument NETH503 5 Digital Theodolite • 5 Digital Theodolite • Magnification: 30x, Stadia ratio 1:100 • Effective Aperture: 45 mm • Resolving Power: 4 • Field of View: 120 • Minimum Focus: 3ft • Measuring Method: Photoelectric Incremental Encoder • Minimum Reading: 5, Accuracy: 5 • Detection Method: Single, Vertical single • Detection Method: Single, Vertical single