The Kessler The Proton's full retail price is €1,270. The Ski costs roughly €670 more than the average price of all All-Rounder Ski, making it a real luxury Ski. Effortless to ride at all speeds, this ski is just right for all intermediate skiers. Available lengths for the ski are ranging between 166 and 182cm. With a radius ranging from only 12 m to 16 m this ski is perfect for short turns and aggressive carving action.