Handheld GM Counter with Integrated Tube

This handheld GM counter with an integrated Geiger-Müller tube detects alpha, beta and gamma radiation. The GM voltage is adjustable from 400 V to 700 V, and readings are shown as counts per minute with measurement periods from 1 to 100 seconds. The mica-window detector is protected by a removable cap and the unit uses a non-replaceable rechargeable 9 V battery.