This is a gift box for fun things, plutonium, condoms, candy... Inside this gift box is a tritium keychain, which glows due to actual radioactivity that is contained and completely safe. It has a nice glow, but it freaks people out if they know nothing about nuclear chemistry. The shell is a coffee can. The inside is filled with salt/sand that I let dry though cement or lead would also make a good filler. The inside is a soup can with the lid cut along the side so it has a nice top. The soup can lid has a tab attached to it so the container can be opened and an old radioactive label on the to make it exciting. I painted the can and sand black for nice contrast. A glow stick or tritium key chain can be used to make it glow inside.