We have 20 total. 10 blue and 10 green. These have a unique glow. They are tritium vial necklaces. Tritium glows all the time. No charging. Just glow. Of course it only glows in the dark. Because these are made with glass tubes we ask that you be sure to be careful with them. These are already made and ready to ship. Once they're gone, they're gone forever. The chain is 27 inches long.