The "glass" part itself is actually 3D-printed medical-grade PLA plastic, the same kind used for heart valves. Since everything tends to float in microgravity, the base hides a 22-pound magnet that can be used to stick the glass on magnetic surfaces. Plus, it has a one way valve where a customized whiskey bottle nozzle can be inserted to pour out a shot. Parr and Ballantine published more details about the design process on Medium, if you'd like to read more about how the "space glass" was created. Sure, it could be nothing but a marketing stunt, but it's amazing how much thought went into designing a whiskey glass. It's unfortunate that most of us might never get to use it in its intended environment; good thing the final product at least looks fancy enough to display.