These knuckles are cast in clear resin with glow in the dark mica powder and black acrylic paint. There is a beautiful heart cut out in it. Turn out the lights and see how this piece glows! These are great for multiple uses including self protection, sensation play, impact play, and more. Turn off the lights for some extra fun! 4 inches Item ships in 1-3 business days via USPS. Tracking information will be provided.