Think Tank Photo has realised that pro photographers and serious shutterbugs have a need for a flexible, multi-purpose field bag, and the "Change Up" is the result of their labour.
This unique pack is capable of changing its form as a belt pack to a shoulder bag, and can even be carried on your chest when you use the enclosed harness system to support it.
A wide, supportive waist belt enables you to wear this belt pack lower or higher on front of the body, or on your hip, and can be rotated around in a snap for the most comfortable position possible while you concentrate on getting the shot.
As the sharp tacks among you may have guessed, the ability to be used for one purpose and changed easily for another is the main reason behind the "Change Up" name.
Size-wise it claims to offer more than ample space and cameras such as the Nikon D200 or the Canon 5D (without the bottom battery grips attached) can be put straight down into the bag with a lens attached.