In your listing for the Viper PST Gen II it says “Vortex Viper PST Gen2 5-25 NP2DD”. What does NP2DD mean? I can’t find anything on the Vortex site that references that. Is this a Mil or MOA scope, FFP or SFP, and which reticle?Thanks for the clarification. Also, why are you selling/trading it in favor of an Arken or Athlon? Has it not performed to your preferences in some way(s)? Thanks