E900 HARDWARE SL728 28 in. Lock-End Extension Spring (0.177 in. No. 7 Wire) SL728-C - The Home Depot
E900 HARDWARE P520 20-Inch Plug-End Garage Door Spring (.207" #5 Wire) - Walmart.com
Macdesign Home System Corp. by Mackenzie Hardware - HOLMES E900 GARAGE DOOR HARDWARE MANUAL LIFT MECHANISM • For one piece residential garage doors 6'10" to 7'4" tall • Heavy Duty Jamb Hardware