This ultra-realistic Crystal Skull is blown with extra-thick 12mm iridescent glass and has some serious weight. The shimmer effect that occurs when it is hit with sunlight is truly mesmerizing. The 15-inch Crystal Skull Bong weighs over 4 pounds and contains a swirling glass tube near the mouthpiece. The 10-inch Crystal Skull Bong weighs nearly 3 pounds and contains a swirling glass tube infused with glow-in-the-dark bubbles that light up when it gets dark. Every piece comes with a high-quality 14mm glass bowl and diffused glass downstem.