I am looking for a very thin whistle to carry in a wallet along with an 1AAA Maglite, Leatherman Pulse, Bic, signal mirror, & compass. Any candidates?

REI sells an aluminum whistle which is 5/16" in diameter and 1.75" long. Reasonably loud for its size.

I have one, relatively flat.
I saved it from a "survival kit" from Victorinox. But I no longer see that leather pouch on their web site.

The ACR whistle is 1" x 2" x .25". Pealess and loud. You can get them lots of places for about $3.

Yes, the ACR whistle is what's on my keychain, it's thin and light, here's one place you can get them online:

http://www.campmor.com/webapp/wcs/stores...mberId=12500226

I have also bought them at the local West Marine store, they meet Coast Guard and SOLAS requirements.

The ACR is also USMC issue in their survival kits. Great whistle...

M

I keep an ACR in my pocket kit and a modified fox40mini in my bag kit. The ARC is nice and thin and fits well in an altoids tin. Fits even better once to cut off the lanyard attachment portion. I have also tried those little aluminum whistles (both sizes) from REI. They are not nearly as loud... not even remotely close to the loudness of teh ACR and Fox40 whistles.