The Volcano vaporization system consists of two valves, Easy Valve and Solid Valve, plus the two vaporizers, Volcano Digit and Volcano Classic. The valves fit both hot air generators, giving you a choice of 4 different vaporizer sets. Here is the important point: Whichever combination you decide on, there is no difference in the effect achieved. The choice is yours! The Volcano vaporizer, by German-based company Storz & Bickel, is the “800-pound gorilla in the room” when it comes to high quality vaporizers. The undisputed heavyweight champ of vapes, the Volcano has set the bar high when it comes to quality, durability and performance. (vaporizerblog.com)