Heavy Duty Industrial Curtain Trolley with Nylon Wheels. The nylon wheels on steel bodies are recommended for curtains weighing less than 100 pounds and under 15 feet tall. These rollers are compatible with the 16RT tracks. The steel hook provides a drop of 2.5 inches below the roller track, and offer a round nest at the bottom of the hook to accept curtains with grommets. Pull Rope Trolleys, recommended for curtains over eight feet tall. Steel Wheel Trolleys recommended for curtains over 100 pounds. Hook diameter 0.25 in.