GARAGE DOOR EXTENSION SPRING SUPPORT: The Richelieu 7740BLBC Garage Door Extension Spring is made of Steel with a Rest Length of 25 in. and a Capacity of 90 lb. The spring has a Diameter of 1/8 and is colored Black. This product comes in a pack of 2. APPLICATION FOR GARAGE DOORS: This Garage Door Extension Spring is designed for use on garage doors, providing the necessary support for smooth operation. The spring’s specifications make it suitable for various garage door configurations.