Come and Check Our Promo Solutions.This waterproof backpack is made of high quality waterproof 30D silicon coating nylon fabric which is also tear resistant. The backpack built-in USB port is convenient to charge your cell phone by the connected power bank . Comfortable airflow back design with thick but soft multi-panel ventilated padding, gives you maximum back support, breathable. Perfects for business traveling, weekend getaways, school,shopping & outdoor activities in daily life. Pls check inventory and detailed info with us before placing your orders.