Bloc-O-Lifts offer adjustment with force support, damping, and progressive locking through the entire travel. This is achieved by a special piston valve system. When the valve is open, the Bloc-O-Lift provides force support and damping. When the valve is closed, the gas spring locks and provides very high resistance to any motion. Bloc-O-Lifts can be locked and held in position with either rigid or elastic locking. Bloc-O-Lifts are available in a wide range of travel lengths and forces. Bloc-O-moreLifts are maintenance free and provide a long service life, even at higher loads. Applications in the Medical and Industrial areas include backrest and height adjustment for treatment tables and beds, steering column adjustment, and exercise equipment. less