1st Focal Plane vrs 2nd Focal Plane… the Difference
The Air Rifle Scopes shown below
are not Spring/Nitro Piston Air Rifle Compatible
Because they have an Adustable Objective (AO) they are capable of correcting Parallex error. When Parallax is properly adjusted, your target looks like it has the Cross-Hairs painted on it no matter where you move your head. Therefore, these scopes have Parallax adjustment. They will not with stand the recoil produced by Spring-Piston or Nitro-Piston Air Rifles.