Specifications EO400 EO410 EO420 EO430   -35 dBm range 850nm Light Source -40 dBm range 850nm Light Source Measurement Range -21 to -35dBm -21 to -35dBm -21 to -40dBm -21 to -40dBm Resolution 0.38dB 0.38dB 0.5dB 0.5dB Absolute Accuracy ±0.5dB ±0.5dB ±1.0dBm ±1.0dBm NIST Traceable Calibrated Wavelength 850 nm Light Source (built-in) — 850nm — 850nm Battery Life 60hr 20hr 60hr 20hr Dimensions (all models) 4.94 x 2.75 x 1.28" (125 x 70 x 33mm) Weight (all models) 5 oz (145g)