Bloc in soft 300D polyester, graphite finishing with a built-in, external auxiliary battery of high charge capacity -4,000 mAh-. In sober design, with magnet closure and metal plate for logo. Plenty of storage compartments to store business cards, USB flash memories, plus a holder case for smartphones/tablets and LED charge indicators inside.. Including a 20-page A5-size notepad. The easy access to the charging station via micro USB cable - included- make of this folder the perfect gadget for business and studying. 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.