The Monitor 4 is a compact, ergonomic, general purpose survey meter capable of detecting alpha, beta, gamma, and x-rays over 3 selectable ranges. It is lightweight and comfortably fits in your hand. The instrument features analog display and an internal end window G-M detector. A red count light flashes and a beep sounds with each event detected.

Specifications:
Monitor 4: Halogen-quenched uncompensated GM tube with thin mica window 1.5-2.0 mg/cm2 thick. Effective diameter of window is 9.1 mm (.36 in.).
Operating Range: 0-.5, 0-5, 0-50 mR/hr 0-500, 0-5,000, 0-50,000 CPM or 0-5, 0-50, 0-500 μSv/hr (SI Scale Meter Option) detects beta at 50 keV with typical 35% detection efficiency and beta at 150 keV with typical 75% detection efficiency.
Accuracy: Typically ±15% of reading (Cs137)
Range Switch: X1, X10, X100, Battery Check. Meter Face Options
Display: Analog Meter holds full scale in fields as high as 100X maximum reading. CPM & mR/hr scale. Optional SI Scale Meter Available
Audio Indicator: Internally mounted beeper (can be turned off for silent operation).
Power Requirements: 9-volt alkaline battery (included). Approx. 2,000 hrs. at normal background
Temperature Range: -20° to 55°C (-4° to 131°F)
Weight: 200 g (7.1 oz)
Outputs: 3.5 mm jack with pulse out.
Size: 209 x 71 x 50 mm (8.2 x 2.8 x 1.9 in.)
Includes: Carrying Case w/ Belt Clip