I have a genuine US Air Force issue signal mirror in my airplane survival vest, Strumalot, but I always kept old CD-ROM's in the glove box of the airplane too, just in case. They work almost as well, and cost nothing. And they make good coasters for your drink once you are done flying for the day....
Just don't use a
rap CD -- no one will want to pick you up if they have to listen to THAT.
Tom, as I flew my airplane down to Idaho for the move, I spent extra days on the ground weather delayed in Whitehorse, YT and Prince George, BC. I made it a point to go to the local CASARA (Canadian Search and Rescue Association) squadron and trade war stories about SAR in the Arctic.