4,000 mAh, external auxiliary battery in nature line, with shell in bamboo wood. USB output and micro USB input -cable included-. Wide printing area and presented in an attractive, individual design box. The 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.