First: The needle models are different (M8: 11 16 24 36 42 needles A8S: 12, 18, 24, 36, 42. The material of the A8S needle is the same as that of the M8S)
Second: Needle details: (M8: straight needle wall, A8S and M8s are wavy needle walls, which are more evenly introduced.)
Third: The charging sockets are different. (M8: round small hole, A8S: Type-c)
Fourth: The battery capacity is different. (M8: 500MAH, A8S: 700MAH, and low battery will alarm)
