Vapolution 3 is the 3nd iteration of the original glass on glass vaporizer. It has set a new high standard for being the only vaporizer to offer a complete glass on glass vapor path with precision digital temperature control, a removable glass heater liner, bigger loads and water filtration. Others claim to offer the benefits of a 100% glass air/vapor path, but they still have metals, ceramics and plastics in contact with the air you are inhaling. Don't compromise flavor or your health. All glass means pure vapor!