Memory by Balala Zheng & Billy YeungMemory is back in stock after more than a year, with increased usability and thinner cardboard for easy tearing. Create an emotional and poetic piece of magic that leaves a truly memorable experience for your cherished audience. Two pieces of cardboard are signed and torn in half by you and the participant. The torn edges fit together seamlessly to form a heart shaped hourglass. What fooled me most with "Memory" is a topological innovation that made