I'm not sure what peoples definition of big is but this bag is not. It is bigger than a typical first aid bag but still pretty small. I was able to CRAM two 1000cc NS bags into the large pocket with two sets of tubing and that is all it would hold. Once the two small pockets roll out a small pouch is revealed where I put a pen light and some trauma sheers. In one of the small pouches I was able to cram in some sterile 4x4's, some tape, band-aids, and an ice pack. In the other I was able to put some basic meds and the rest of an IV start kit, enough for two bags if needed. I was able to put a stethoscope under the main flap when it is all put back together. That is it! If you want this bag to hold more that what I have described then I suggest you get a bigger bag. I do like the straps on the back that will allow the bag to be secured to another bag or anything else you want to strap it to. The bag does appear to be made of quality material and the zippers work very well even when pushed to the limit. I have not been able to really test it in heavy use yet though. Overall a great bag that will serve it's function well. It makes for a good quality "advanced" first aid kit that does not take up a lot of space. If you are planning on getting this to attach to a hiking pack I suggest something else as this bag empty is a little on the heavy side. I got the red which comes with a cross velcro patch that you can replace with any patch of you own if you want with out sewing one in.

It's a nice pack and can hold lots of items. But it would be nice if the rear pouch was larger. It's about 1.5 inches taller and 1/2 inch deeper. That would keep from having to bend a chest vent patch or burn blankets. The front pouches are nice in size but adding any saline over 200 mill into the space between the mid and rear pouch is hard.
Overall it's a good pack. When setting it up the further into it you dig the worst the situation you are dealing with.

Others have stated that it only has three compartments and you have to dig to find things.
I bought it anyway. When it arrived I thought.... this thing is HUGE, going to have plenty of room....... Just enough for everything on my list.
2 of the 3 pockets lay on top of the larger pocket and the flap (with buckle) holds it all together as pictured.
The 2 front pockets hold my "everyday use" items: bandaids, ointments, medicines, etc.

I bought a Plano organizer from Wal Mart for $5.48 to organize / stores all the different Band-Aid sizes, bacitracin, tums, aleeve, Tylenol, claritan, Iodine, aquaphore, chapstick, small scissors, tweezers, finger splints, safety pins, and a few more small items. This is in the first pocket.
The second pocket holds sunscreen, bugspray, alcohol wipes, 2x2 and 4x4 guazes, gloves, tape, mole skin, razor blades, and a few others.
In the large compartment: Sam splint, ace wraps, chem lights, head light, emergency blanket, razor knife, thermometer, Epi pen, and several other items I can't think of right now.
The pack holds it all perfectly. It folds up nice and fits under the second row seat (suburban) perfectly!
With 3 kids in activities from football to gymnastics, this pack will see a ton of use. Shouldn't have any problems keeping up with items that have an expiration date.
The bag itself had a good sturdy handle, shoulder strap, and mole straps if you go that route.
No it doesn't have individual pockets for each and every item, Yes it has room to pack each and every item.
For the price, it is perfect, I am satisfied, and I would recommend this to anyone, anytime, for any reason...
Good luck on your decision.

How I set my bag up

the first fold out has 2 tourniquets and 2 pressure dressings

the fabric 'bridge' between the first and second pouch has a small flash light and sharpie pen clipped on

the second pouch has chest seals, NPA / lube , OPA - an IGel would fit IF it was out of factory pack.

the open 'pocket' on big third pouch has stethoscope and a couple glow sticks and trauma shears

the big pocket has Pocket BVM , BP Cuff , zip lock back with boo boo stuff - 3x3 pads , Band-Aids , tape , mylar blanket,

This medic bag seems to be very well constructed. I was skeptical in ordering a product of China fearing poor quality; but don't let that stop you from purchasing one. The three zipper pockets are well placed and allow for compact storage - no huge lumps when putting this together.

I should have read the dimensions prior to purchasing. If you were planning on this being a nice addition to your luggage, think again. This item is BIG! I fit every pill bottle, bandaid boxes, basic instruments, athletic tape and emergency toiletries in the bag. All together it occupies not even two of the three compartments. If I were to pack this in my gym bag, it would dominate the space.

Whether for sheer organization or transporting supplies, I would recommend this product to anyone with a large stash of First Aid goodies.