A first focal plane (FFP) optic means that the reticle is located in front of the magnification lens. This means the reticle will change in size relative to changes with magnification. A second focal plane (SFP) optic means the reticle is placed behind the magnification lens. This results in no change in reticle size as the magnification is adjusted. All PFI scopes are designed in FFP. We want the user to have the full capability of their weapon systems at any magnification. Whether on lowest or highest magnification, the impact holds and other data in the reticle are true. Whereas in SFP optics, the magnification must be set at a specific setting in order for the reticle data to be accurate. At PFI, we know as experienced shooters that there are times when different magnification is necessary for the engagement.