Quiet Operation. The Synoris garage-door opener is the most popular opener in Europe, claims the manufacturer. Now it’s available in the U.S. It has an unusual design: Instead of a belt or chain lifting the door, the 24-volt DC motor itself travels along the central rail, hauling the door with it. Because the drive gear is the only moving transmission part, the product is much quieter than most openers, says the company. It costs $200 and up. Sommer USA, 877/766-6607, sommer-usa.com.