Garador DC / CM Garage Door SpringWhen replacing garage springs, it is recommended to replace both springs at the same time, to ensure the spring tension and door remain balanced. Garador Genuine DC CM type spring is to suit DOUBLE canopy doors with two springs down either side. These doors have horizontal tracks, when the door is open it sticks out approx one third of its height. You can identify that your door is a DC CM type as the lift arms are straight not to be confused with