Use: #703 Vertical Lift Door Hardware is designed for manually operated light or medium sized straight vertical lift doors weighing up to 900 lbs. each. Heavier doors require an electric operator to move.
Operation: The door is counterbalanced by weight boxes on either side of the door. Each weight box is housed within a vertical tubular steel support column that is to be properly braced at the top to prevent sway. These support columns also act as a the door guide during operation. The door and weight box are connected using industrial grade roller chain.