The ones I'm using are about an inch long and what I would call a moderate tension. I will send you a photo as soon as I get my camera back from my daughter. Guess what she is getting for Christmas?

The main point of this spring is to take the shock of any sudden jars away from the servo gears if you hit anything . But you should be able to get a pair for about a buck at most hobby stores or hardware stores. I got mine at a place out my way that handels surpluss electronics and such. This place has so much stuff it took me a hour just looking around. They also had a bazillion tiny rivits.

Steve