The only mask I can comment on from personal use is the Laerdal Pocket Mask. It is kinda big and clunky for EDC, unless you EDC a fair sized bag of some kind, but it works, and works well. If you happen to have an O2 bottle handy, you can hook the line up to a port in the mast and blow more O2 into the victim. Before they added the one way valve I saw a victim vomit into the mask; once the CPR'r got out of the way it looks like Mt. Vesuvius in Technicolor. I have several different brands of little bitty CPR masks that I carry around with me, but I have luckily never had to use one. And rule number one in the wonderful world of CPR is to NEVER EVER perform bareback CPR on anyone but a family member...