The reflective surface present on CD's is a perfect quality that we can use in laser light shows, Christmas decorations, and hundreds of other uses. However, one of the simplest uses for the Cd's special qualities is a simple signal mirror.

You can use the CD the way it is as a signal mirror, or you can reshape it for your purposes. I am in favor of reshaping it because the product is consequently smaller and allows you to save space. This also helps to stow the mirror in one of the many Altoids can survival kits featured here on Instructables.

You can follow this Instructable, or watch the video explaining how to do the project.

Step 1: Materials

What you will need:
-A CD (that you do not mind breaking)
-Tape

What you will use:
-Knife/scissors
-Cutting board
-Marker (Sharpie?)
-Ruler

Step 2: Video

Here is a video explaining how to do the project, and the following steps should help explain anything that you missed in the video.

http://www.youtube.com/watch?v=EKbkRTCMtC0

* I wasn't able to embed the video in the Instructable for some reason. I will try to correct it.

Step 3: Shape the Mirror

Like I said earlier, I wanted to shape the signal mirror to fit in an Altoids tin. To do this, mark out the shape of an Altoids tin in the center of the CD. The dimensions of an Altoids tin are :2.25" deep (front to back), 3.5" long (side to side), 0.75" inner height (from inside bottom of tin to rim)

Remember: if you want the mirror to fit in the tin, mark it slightly smaller than the tin itself.

Step 4: Cut the CD

Use the knife to score the dimensions of the mirror in the CD. Cut the CD as thin as possible, and you can use the edge of a table to "snap" off the extra material. Or you can cut the CD using scissors.

Step 5: Tape Time!

To finish off the project, cover the edges in tape to prevent the reflective coating on the CD from peeling off. Using the tape, you can also make a small loop at the top of the mirror to make it easier to attach to something with a carabiner or paracord.

Step 6: How to Signal

To signal with the CD, sight the target that you want to signal in the hole in the center of the CD. Then wag the mirror back and forth to produce a reflection. You can do much more with a signal mirror, including communicate in Morse code among other things.
Enjoy your new survival tool!