Most air rifles have a mount that will make it easy to install a scope. This video will help you to choose the appropriate scope and how to mount it. You will need an air rifle rated scope so that the recoil does not break the piece. You can attach a mount to the rails or a two ring system. The mount is stronger but the rings are more flexible. The size of your scope will be determined by the type and size of your gun. A spring air rifle will need with adequate recoil abilities. Screws should not be overly tightened and you can adjust your scope to be set correctly and leveled. Tighten your scope securely without stressing the set up.