Specifications include, but are not limited to: Detector: Pancake GM (Geiger-Mueller) detector, stainless steel screen (79% open) WINDOW AREA: Active: 15.51 cm² (2.4 in²); Open: 12.26 cm² (1.9 in²) EFFICIENCY (4π): Alpha: 11% for 239Pu; Beta: 18% for 99Tc; 32% for 32P; 2% for 14C; 22% for 90Sr/90Y; 0.2% for 125I; Gamma: 3300 cpm/mR/hr or 5.5 cps/μSv/h (137Cs); ≤1% for 99mTc RESOLVING TIME: approximately 110 microseconds as defined by IEC 60325 ALARMS: count rate and scaler alarm set points adjustable over the display range OVERLOAD: high count rate saturation protection prevents false display of lower count rates ZERO PROTECTION: after 60 seconds of no pulses from detector, unit will flash a zero reading and the alarm audio will be triggered LCD DISPLAY: 3½ digit LCD with large 12.7 mm (0.5 in.) digits, (k)cps, (k)cpm, (k)dpm, (k)Bq, mR/hr, µSv/h, Bq, and dpm; low-battery indicator, MAX, ALARM RANGE: 0.1 cps to 19.9 kcps, or 1 cpm to 999 kcpm, 0.0 to 500 mR/hr, 0.01 to 1999 µSv/h; 0.1 to 19.9 kBq; 1 to 999 kcpm BACKLIGHT: built-in ambient light sensor automatically activates low-power LED backlight, or may be configured for ‘Continuous On’ operations (will reduce battery life).