Chamberlain CG40D 1/2-HP Chain Drive Garage Access System
The Chamberlain CG40D 1/2-HP Chain Drive is steady and reliable. Its durable 1/2-HP motor and chain drive provide continual steady performance. Auto force-sensing technology constantly monitors garage door opener system and adjusts forces to temperature fluctuations, floor height and door track movement. Enclosed gear case provides continuous lubrication and protection for longer life and smoother operation. The Protector System safety sensors with Rapid-Snap brackets project an invisible light beam across the garage door opening and automatically reverse the door if anything interrupts the beam while the door is going down.