Submitted by scottmurphy
I have 3 different signal mirrors. The one I like the most is the ACR Electronics Hot Shot Signal Mirror. It puts a "red dot" site on the target you're trying to signal. This helps you line up the sun, mirror and target. I've used it to signal overflying aircraft with a lot of success.
ED -- SM, I can't fault you on your choice of mirrors. The ACR is an excelent mirror, and as you said, it has the "red dot" feature to assist you in aiming. One other thing I like about this particular lash up is that it comes with a whistle and a float, so you can take it on the water with you.