PD Meter 1.Use battery,long life 2.Power off automatically . 3.blue ,gray,black three color. 4. ... positioning and accurate dataLED light source, low consumption and long battery lifeMany technology and design patentsMAIN TECHNICAL INDEXES1,Range of data ... ,Distance of target30cm~∞6,Power sourceVoltage:DC 6VSpecification: AA batteryQuantity:2 pieces7,Time for automatic shut-off1 and a half minutes ...