... , power light 4, prepare light 5, power switch/adjustment knob 6, battery cover Technical characteristics: 1, pocket with then handheld. 2, nondestructive ... testing, easy operation accurate. 3, working power supply: DC9V battery. 4, physical size: 160 * 40 * 22 mm weight: about ... please don't try to open in addition to the battery cover outside of the anything! In order to avoid damage ...