You can read more about the medium size bag and what you can fit in it, in this Professional Photographer article: http://www.ppmag.com/web-exclusives/2012/11/style-bags.html
The bag comes with loads of pockets for all the small accessories. On the outside the bag has two rivet reinforced pockets under the flap, one pocket at each end of the bag and a large pocket on the back side. Inside there are 4 more pockets.
The bag comes with a removable padded insert for the camera and lenses. The insert has two adjustable dividers with velcro attachment.
The detachable brown leather strap is fully adjustable between 50" and 28".
Height: 7 1/4" (18.5cm)
Width: 10 1/4" (26cm)
Depth: 5 1/2" (14cm)
Height: 7" (16.5cm)
Width: 10" (25.5cm)
Depth: 5" (12.5cm)