I'm trying to figure out what this insulator might be worth. I only have 2 other suspensions so I really don't know much about their value. The insulator is the 10" variety, and it stands 7" high. My uncle bought me this for my birthday awhile back and I'd like to get around selling it. There are a few markings on the cap which read "SED 71" and then on the other side, "15,000 pounds." Any info on the approx value would be appreciated. Thank you.