MQ-50S is palm size portable 5000mAh polymer power bank. It is our factory new private tooling specially designed for gift promotion. It’s made of pure cobalt polymer lithium battery, more than 500 times battery cycle, and over one year standby time. This PCBA board has an intelligent multi-protection systems, such as over current protection, over voltage protection, over charging protection, over discharging protection, short circuit protection, etc.,that ensure complete protection for our product and your charging devices. High transfer efficiency 65% which could full charge your phone one time.