A bag with dimensions of 12x24x12 would have 3,456 cubic inches of total capacity. This product spec states 3,114 cubic inches and is incorrect. 5.11 Tactical got the volume calculations correct on the NBT X-Ray bag, just not this one.
However, overall it is a nice duffle bag.
I've been using this bag for a couple of months now ans like it. I work armored car part time and use the bag to keep my lunch, extra rounds, basic first aid kit, a change of clothes and personal medical supplies in and now that it's getting colder a lightweight jacket, and there's still room. The only things I would like see different are a better padded shoulder strap and some type of semi rigid, removable bottom inside. I also keep my armor in it if I'm driving.
Overall, I am pleased with this purchase. Basically, it's a tactical style gym bag. Very spacious and good placement of handles make it easy to grab and go. I personally carry it in the trunk of my patrol car for my spare uniform, toiletry kit, medical kit, towel, etc. for long days or unexpected call outs. Would get 5 stars except there is no structure to the bag, meaning its flimsy and collapsible. I personally think a little bit of structural integrity (like a thin base inside or stiffer corners) would help keep the bag open for packing/unpacking. All my LEO and military gear is 5.11, and the quality lives up to the standard operators require. Therefore, I have much to compare this product to. Overall though, it's a good bag.