What Certainteed Coil Springs do I have?

Yea I am a homeowner that had windows installed about 20 years ago. These windows were Certainteed, I believe Devon was the style, double hung window tilt down. We have 2 windows that will not stay open when the bottom portion is lifted up and are looking to fix these. If you could help identify the parts we need that would be great. If the parts are even still manufactured.
The pictures included are from the part that came out of the window. The only number we could see on the part is "407" on the silver coil. The plastic had no identifiable markings.