With Model DX-1, elevated radiation levels are indicated by beeps, beginning above 10 mR/hr, and decreasing in interval to become continuous above 20 mR/hr. Able to be recalibrated via backside adjustment screw, Model DX-2 compacts several ranges into one scale for measuring higher levels of radiation. Both meters have single pushbutton for activation, LED indicator for battery, internal speaker, and compressed-scale meter.