I wear a vest. I took the vertical upper heavy strap in the back and installed a 1/4" grommet so that I could attach it, using S-Biner clips, to the D rings on the vest, leaving the vest pockets for other uses. P size filters must stand vertically, and as a result, the top flap barely makes it over to the matching Velcro leaving a big gap between the body and top flap. Although not shown, there are two heavy cross-over ~2 inch flap sets that attach via Velcro. One set is vertical, one horizontal. These should work well with the appropriate mounting. It is a very compact bag.
Does a great job of securing large filters. Since the pouch is a bit bulky, the ability to fasten it securely to the accessory strap on my camera bag makes it easy to transport.