In essence a blade of pure energy capable of cutting through almost anything, the lightsaber is the noble yet powerful weapon which the Jedi Knights have masterfully wielded for thousands of years. Although each lightsaber is unique, the weapon's basic design remains the same. The handle, twenty-four to thirty centimeters long, holds a power cell as well as one or more crystals - seldom more than three - whose purpose is to focus the energy released by the power cell into a tight, blade-like beam. The blade's color depends on the nature of the jewel it springs from, and while its length is fixed in the case of a single jewel lightsaber, lightsabers equipped with multiple crystals can have their length varied by rotating a knob which allows the focusing crystal activator to subtly modify the refraction pattern between the gems. After losing the lightsaber that had been his father's in a duel with Darth Vader, Luke Skywalker, in accordance with tradition, builds his own lightsaber as one of the final steps of his Jedi training, before he confronts Jabba the Hutt in his palace on Tatooine.