Time to give your AEG a new spring in its step or take it from sub par performance to tuned up for battle with this great range of colour coded springs from M95 to M135 for bolt action rifles. Made from military specification spring steel (SiCr) the best steel for springs of this type with progressive coiling to give you a soft start reducing stress on mechanical and electrical parts. ASG Ultimate Upgrade springs are pre-compressed which reduces power loss from initial shrinkage.