Dr.pen M8: Known for its powerful and consistent performance in microneedling treatments. Standard control interface with speed and power buttons. Generally has good battery life, suitable for multiple treatments before needing to be recharged. Dr.pen M8S: Has an enhancement in motor power or battery life, providing more efficient or smoother operation. Has an improved or more user-friendly interface, possibly with a digital display or more intuitive controls. Has a longer battery life or faster charging capabilities, making it more convenient for frequent use.