Note: Not compatible with Oura rings, NOT for Smasung Ring, NOT for ultrahuman ring, NOT for RingConn ring. Wide Compatibility: This universal magnetic charger is compatible with most 1 pin magnetic charging devices, including smart rings, small appliances, and lighting equipment. The charging ring diameter is 4 mm. Measure device charging contacts before purchasing. Safe Charging: High-quality aluminum alloy+PVC material has good durability. The integrated smart chip enhances charging efficiency while protecting your smart ring's battery, delivering safe and optimized power without overcharging Strong Magnetic Design： Built-in pure copper probe with solid magnetic power supply, stronger adsorption Ring charging than other chargers. Portable and ECO-FRIENDLY：The charging cable is designed to be lightweight and portable, so it can be put into your travel bag and carried around.Adopting high efficiency conversion circuit and low power standby mode reduces energy consumption, minimizing energy waste and carbon emission.