A: The flagship model comes standard with [send original 9V dry battery] B: Flagship model with high configuration [Send original 9V charging set] C: Voice type multifunctional measuring instrument [wall detection + ranging] Maximum detection depth: Magnetic metal: 12 cm Non-magnetic metal: 10 cm Alternating current: 5 cm Wood: 3.8 cm Battery type: 9V universal battery Operating time: about 6 hours Automatic shutdown: automatic shutdown within 5 minutes without operation Detection depth: Ferrous metals: 100mm Non-ferrous metal (copper): 80mm Alternating current: 40mm Copper wire (≥ 4mm2): 40mm Foreign body (- generally refers to wooden block): 20mm (EXACT/precision), 38mm (DEEP/depth) Battery type: 300mAH built-in rechargeable lithium battery Battery life: about 5000 times in a single measurement Automatic shutdown: automatic shutdown within 5 minutes without operation