Ventir is a modular backpack system that changes its configuration to fit your carrying needs. Most people use one backpack for everything, but find it’s too big for daily use and too small for an overnight trip or gym visit. Ventir has a slim “Core” backpack onto which you can attach 1 of 3 additional bags. Use Core on a light day. If you have a heavier day, zip the “Basic” bag onto Core. If you plan to go to the gym or have a trip planned, add the “Gym” or “Travel” bags. Regardless of your carrying needs, Ventir can be adjusted to meet them.