Pattern Haskins/Starfleet Blue Spring
A replacement spring to suit Haskins/Starfleet garage doors 3048mm (10` 0″) wide to 4267mm (14` 0″) wide.
The spring has 71 coils. with a length over coils of 464mm (181/4″).
An overall length of approximately 540mm (211/4″) including hooks and an outside diameter of 54mm (2 1/8″).
Springs are sold individually. although best working practice suggests that they should be replaced in pairs to ensure a properly balanced door.