Here's another case for a PSK. Its the Band-Aid Tough box that was filled with Tough Strips Band-Aids. Its Polypropylene plastic. Nominal 4 1/4" tall by 2 5/8"wide 1 3/4" deep. The hinge is molded to body which will probably weaken from fatigue. Its pretty stiff overall.

We have one of those, still has Band-Aids in it. Nice shape, etc, but it seems to like to open on itself, so for a FAK/PSK I would suggest some tape or something to help it stay closed...

If you'd like something about this size and volume, try one of the Witz sport cases - they come in clear and solid colors. They are completely waterproof/tight and have a top with a good hinge and clasp. They also have a loop on top for lanyard or carabiner carry. I have an Atwater-Carey personal first aid in one and Doug's survival kit, with some additions, in another. I also keep my cell phone in one when out in the wet and wild, my Garmin Etrex Vista in another and a small Sony AM/FM/weather band in yet another. The ones I use for the phone and GPS have foam padding. Witz also has smaller, thinner cases for carrying ID, credit cards, cash, etc. I have other several Witz cases, ranging in size from comparable to the band-aid box to a small chest. Very good cases all, waterproof/tight inexpensive, and highly recommended.