Camera sling bags have developed from backpack camera cases and are quite popular with photographers for the easy access they provide to the gear. The Think Tank Sling-O-Matic 10 Backpack is an innovative solution to the problems that sling bags pose.It is the first of the camera sling bags in the photo industry that can be worn on either of the shouldersThe fully-padded shoulder strap of the Think Tank Sling-O-Matic 10 Backpack is adjustable and allows for easy change of the shoulder in one smooth movementThis camera bag is provided with a set of rails along which the shoulder strap slides and lets you easily change the shoulderIrrespective of the shoulder you wish to carry the Think Tank Sling-O-Matic 10 Backpack on, if it is in the front, then the gear access always remains on topIt can hold any of the regular size and some of the pro size DSLR CamerasIn addition, you can either have a 70-200 f2.8 attached with lens hood in position or 2-3 additional lenses with a flashIs not suitable for all Nikon Pro DSLR camerasWeighs 2.3-3.1 lbs (1.0-1.4 kg)Internal measurement: 8.25" W x 15.5" H x 5.5" D (21 x 39 x 14 cm),  but flexible enough to accommodate some pro size DSLR cameras with the lens attachedExternal measurement: 9" W x 16.5" H x 6" D (23 x 42 x 15 cm)