Dump pouch, usually used for empty magazines, but can be used for other things. I have noted that the ones the Ukrainians seem to prefer using are on the larger side, but they do primarily use AK platforms which have larger magazines than the M4/M16 platforms I am more familiar with so it could just be my perception. The downside of the larger dump pouch is that it can get caught on things, especially in CQB situations imo