Boot designer Sven Coomer later improved the design with a corrugated tongue, and this technique was commercialized by Comfort Products, an Aspen, Colo. company owned by the ex-ski racer Erik Giese. Giese licensed Coomer's concept to the Swiss company Raichle-Molitor; the company introduced it in 1979 as the Flexon, which became very popular among downhill racers and mogul skiers. The Flexon was extremely popular among professional skiers, especially for moguls and freestyle, but a series of business blunders put Raichle out of business in the late 1990s. Several companies produce three-piece designs today, often referred to as "cabrio" boots (after convertible-top cabriolet vehicles), and they are once again becoming popular models.