WOW! I got this pouch today and tested it out. First thing you need to know is that it's BIG. I was planning on putting it above my mag pouches, but it would have blocked access(NOT a con, just poor planning on my part), so I had to move it to the back of my pistol belt.
To give you an idea of just HOW big it is, I fit 2 green gas cans, 10 CO2 canisters(the small ones), and about 1300 rounds(1/2 of a 2500 rd. bag) inside. You could squeeze a bit more in there, but that was pretty full. I put it back on my pack and jumped around some to make sure it was secure and it stayed fine. The velcro would have come off except for that buckle that holds it nice and tight.
This pouch is great if you need to carry extra gas or ammo or other large objects into the field. Heck, I think it's big enough to be a drop-pouch, though that'd be impractical.
To my surprise, I found it very secure. I don't think there's any chance this would just come off in the field. The velcro and buckle together secure it quite nicely.
BIG... VERY VERY BIG!
there's a spot for anything/everything you'd need to carry.
OE Tech(AKA Condor Outdoors) is a very good brand, all of my MOLLE stuff is from them.
Didn't work where I wanted it, but that was my fault.
bigger than I expected, so if you don't want the extra room, I recommend the OE Tech MOLLE EMT pouch, kinda the younger bro to this pouch.