Note: The maker supplied a review sample for evaluation, the opinion of the product is my own personal viewI had some reservations with this bag when it first arrived rather than a normal front opening this one has two side pouches (as well as numerous other pockets and compartments) Inside you'll find 3 padded (with plastic reinforced) Velcro panels this allows you to customise the main compartment to suit your needs. There are some clever touches to this bag and quite a lot of thought has gone into maximising the carry load and providing additional pockets for accessories and other items.To start I will give an approx. indication of the sizes and layout of the bag:- Size 34cm wide by 26cm height, depth is 14cm- Front pocket has a single small zip providing a "tear shaped" area with a quick release buckle on top- Behind this is a curved zipped enclosure inside are 2 pen sections and one large/medium pocket- Last front section has thick padding on both sides and soft lining it's the same size as the bag width and height (easily fit a tablet in here)- Largest compartment is accessed by two side flaps these have fabric sewn to zip ends double zips on both sides Velcro at the top padded on all sides- Both side flaps have 2 Velcro topped pockets 7cm tall by 6cm wide clearly aimed at battery/memory card storageMoving to the back a mesh padding here this has a Velcro fastening it's possible to put a few large items here (rain cover would be the obvious one or the wait strap, avoid small items as it has a larger opening) Main strap is padded with various fabric loops (1 horizontal and 1 vertical") D shaped plastic rings 2 of those. Below this is another waist strap this has an adjustable area and should fit waist sizes up to around 40cm this provides stability to the main pack if the shoulder sling comes off it will hold the bag and prevent it falling.Bottom has two adjustable straps to hold a monopod or tripod, a top handle for carrying is a thick but flexible plastic . On the right side 2 black elasticated ties with can be pulled in via tensioners.It would be difficult to think of how to add more pockets to this bag it's loaded and that can is generally a good thing plenty or areas for a tablet/phone, filters, charger and batteries and cards. How much can the main compartment hold? I loaded up an A77 and 17-50mm lens that fit easily into one side, a full sized flash the other side with room for another mid sized lens in there too. If you take the flash out you'll be able to fit another medium size lens in there or a few shorter primes so I'd say 1 camera body and lens, 1 flash and one additional lens or 1 body with up to 3 lenses and no flash.. It is possible to squeeze a smaller body in there so 2 cameras 1 with a normal zoom one with a short prime might work too.Cameras and lenses vary hugely in size if you're using full frame stuff then expect a bit less space and obviously this isn't designed for longer tele lenses (a 55-200 or 75-300mm will fit or if you take the padding out you'll get an F4 70-200mm in there just about) If you shoot with a system like micro 4/3 you could happily fit 2 bodies and 3/4 lenses in there or 3 lenses and a more compact flash this could be a great bag for ILC users as well as DSLR ones. Bags are always a compromise in space and design this is more than enough for a day out or a travelling bag.Topping it off is a WR cover to protect it from rain this has a small pocket 11cm wide by 9cm tall the idea seems to be to fold up the cover into this area when not in use and store it in the bag though you could also put a filter in here. You can wear the bag over the shoulder, behind as a backpack of move it around to the front to access the side compartments.Quality of materials and workmanship is above my expectations for a bag in this price range it's extremely well made and designed even to the point where they have made the straps from reflective material. They've really done their homework on this bag thought of almost everything. The only area I'd change is maybe a larger zip on the front compartment. Don't be put off with the odd design this works much better than I imagined and it's not only different but works well from a practical perspective too. A great bag and a steal at this price