These are handmade D20 resin pendants with the #20 side centered on the pendant.
Green rainbow mylar shifts colors inside these based on light source. Blue or green acrylic paint is uses for painting numbers over a white base paint
Pendant comes on black cord chain (18" long with a 2" Extender & lobster clasp) or 18" silver tone nickel free chain with barrel twist clasp. If you see it comes on a chain and you want it on a cord instead (or a chain instead of a cord) just note that in the purchase notes. IF YOU DO NOT NOTE THIS IT WILL COME ON THE CHAIN/CORD IT IS PHOTOGRAPHED ON.