I picked up an old crappy one at a surplus store a while back, i was told it was for Thompson SMG .45 mags, but the g18 mags fit decently. It holds 4 mags and is certainly not a concelable item. It had ALICE clips on it when I bought it.
I picked up some black ballistic nylon and stopped by a local shoe repair shop and showed him what I wanted and he made me up three, nice four magazine pouches. He added some black EZ snaps and some belt loops. Not bad the whole project cost me $25.00
I called about B/H pouches and they stated they were not sure the the flap would close on the Glock 33rd magazines. They said to buy one and try it out, Great C/S. I asked for them to check before I ordered and they stated they didnt have time to field test each product they sold.