Hand Boiler (Pack of 2; Age 10+) - great for understanding thermodynamic principles Hand boilers use thermodynamics to actually appear to boil Uses just the heat from the hand of the user to boil liquid! See our science & experiment kits: drinking bird, hand boiler, solar windmill, mirascope, liquid timer, kaleidoscope, teleidoscope & bug viewer under separate listings A classic science toy Pack of 2 - colors may vary; Suitable for Age 10+. Contains glass - NOT a toy