4,000 mAh, high charging capacity and resistant external auxiliary battery for solar recharging. Water resistant and silicone coated with a sporty design, especially designed for outdoor activities where there is no access to an electric charging source. Featuring dual USB output for charging two devices simultaneously and charging indicators. With a powerful SOS LED signaling light, designed for emergency situations. With aluminum carrying carabiner and including a resistant micro USB cable. Available in a wide range of colors. Presented in an attractive 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. Blocking system to prevent short circuits. Constant charging transfer system, in accordance with the capacity of the target device.