The spring only fits if it has custom fitted guides and it works quite well. There is no spring that is a drop in replacement for the Gamo's other than a stock spring. The Quest spring fits but is a smaller diameter, the e2000 fits on;y with custom guides, and also the e1500 is the same.
I do not make just a guides because they are fitted to each spring kit I sell, it is not worth the trouble because it would not be any better than a sloppy stock guide. NO spring works at it's max WITH OUT fitted guides.
The prices are on my web site, link is on the bottom.http://home.comcast.net/~peterdragin/index.html/