According to an article on Dezeen.com, the Capsule hourglass, which is filled with microplastic collected by Neill from beaches in Tasmania where he grew up, is an open-edition piece.
"The hourglass seeks to draw attention to the scale of the problem of plastic pollution," Neill told Dezeen. "I work with a global network of NGOs, environmental agencies and beach combers who work diligently to clean up our beaches. Each individual hourglass will hold plastic collected from these partnering sites."