The materials and manufacturing are very good quality. The dimensions listed in the product details are the external measurements. The inside measures approx. 3 W x 3 D x 5 H. I read other reviews on this product saying it is a perfect fit for Canon S1, and I agree, although it is a snug fit. You wont have room for anything else besides the camera in the large compartment. You will have room for batteries, memory card, usb cable, etc in the front pocket, but you wont have room for any other larger accessories. If you want to fit a battery charger or lens adapters forget it, get the Tamrac Digital 6 instead.
Please note, this camera bag will *NOT* fit the Pro1.

Fits the Canon S1 IS perfectly. It has room for an extra compact flash card and an extra set of batteries. Much better than the Canon case for the S1.

My somewhat older Toshiba PDR-M60 camera fits in this case very nicely. Has space for four additional batteries and a SmartMedia card in the side pocket too. I'm very happy with the materials and finish of the bag, and it looks good - albeit a bit bulky, since it has plenty of padding. But this was a great purchase for me. If you're looking for a case that has about 5 x 3 x 2 1/4 " internal dimension, this will do fine.
Also, the color of it is much darker than the picture suggests - looks better in life for sure.