This is a 1" extension spring made from .009" music wire with approximately 110 turns. It is perfectly matched to the rotary dampers I carry and weigh .45g each. With this spring you can easily get 4 minutes from the small G2 dampers and 2 minutes from the tiny E2. If you are careful in your set up, you can get almost 4 minutes from the E2s!
The springs come without loops so the length can be adjusted to fit the application. to make the loops simply slide a pair of small needle nose pliers in between the send and third loop from and end and bend.