Snow lances generate snow in the same way as fan guns but at a greater height (by means of lance tubes). Current lance tubes measure up to 9 meters in length. The drop height is required to crystallize the snow flake, because as opposed to the fan gun, there is no propeller, or turbine. This means that projection distances are much shorter and wind sensitivity is greater. The quantity of snow produced by a lance is similar to that of a small fan gun. Lances are generally used as complete systems, equipped with a central pneumatic system.