Resistant, 300D polyester folder with built-in 4,000 mAh external auxiliary battery. In sober design and with original closure, including a printing surface on the cover especially designed for laser printing, illuminating the logo. Plenty of storage compartments for business cards, USB sticks, plus a wireless charger/case for smartphones. LED charge indicators and USB output for conventional charging. Including a 20 sheet notepad and a support for mobile devices. The easy access to the charging station via micro USB cable - included- make of this folder the perfect gadget for business and studying. Presented in an elegant black 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.