External auxiliary battery of 4,000 mAh made of aluminium. With USB output and, and Type C input and output. LED charge status indicators and charging cable included. with instructions manualin English and Spanish.Micro USB input: 5V DC 1ªUSB output: 5V DC 1AThe capacities shown in all our external auxiliary batteries are real, all of them incorporating non-recycled, grade A batteries, with a service life of at least 500 charging cycles, and complying with CE regulations. In addition, they are manufactured according RoHS standards, and in compliance with the following safety requirements: Power bank overcharge protection system. Complete discharge protection system, which increases the durability of the power bank. Blocking system to prevent short circuits. Constant charging transfer system, in accordance with the capacity of the target device.