Specifications include, but are not limited to: Ludlum Measurements; Model 2241-3 SUGGESTED DETECTORS: GM, proportional, scintillation ALERT/ALARM: indicated by annunciation on display and audible tone DISPLAY: 4-digit LCD backlit display with 1.3 cm (0.5 in.) high digits, separate annunciators for display units, alert, alarm, low battery, detector overload, counting overflow, and scaler counting RATEMETER: can display in R/hr, Sv/h, cpm, or cps when selector switch is in RATE position ; Ludlum Measurements; Model 44-9 INDICATED USE: alpha, beta, and gamma survey; frisking, sample counting DETECTOR: pancake-type, halogen-quenched GM COMPATIBLE INSTRUMENTS: general purpose survey meters, ratemeters, and scalers WINDOW: 1.7 ± 0.3 mg/cm2 mica ; BICRON FRISK TECH Indicated Use: Area monitoring Display: Analog Display Range: 0 - 500 Display Scales: X1, X10, X100, X1000 High Voltage: Adjustable (detector dependent) Audio: Analog volume adjustment Response Time: Variable.