keychain design with 5000mAh capacity, compact size to facilitate travel, so as to solve the need for emergency electric. -intelligently turn into sleep mode when no working, keep the energy consumption the least to maintain its long charging power. -multiple protection to ensure security. Short circuit protection, over-heat protection, over voltage protection, over charge protection, magnetism protection, over discharge protection. -when connected to devices, the power bank would detect and indicate how much power the device need to ensure fast and reliable charging. -ATL lithium ion electric core effectively avoid heating, leaking and explosion, plus its lighter and smaller.