The Bolt Spring is used with all level 7 bolt types on all AGD markers regardless of age or type. They are made from very special square wire so they don't fold inside themselves when collapsed. This spring is also the standard set-up with the Level 10 bolt when you are shooting normal paint. Consistent shooting with 3 star and even 4 star level paint is possible with the Gold Spring. It is the most gas efficient spring to use with your level 10. Replace your old spring if it's been stored compressed in the marker for more than a year, used for more than a year or sags well below the front of the bolt and you are experiencing bolt return or barrel leak issues.