These are a custom labeled 308 BDC knob from the Leupold custom shop. They are calibrated for the typical 308 Match ammo shooting a Sierra Match King 168gr bullet at 2650 fps at a good all around environmental conditions of 2000′ altitude and 59 degree. These knobs are a direct replacement for the factory knobs and are easily replaced by just removing the three set screws from the old knob, lift it, and put this knew one on the scope. They will fit any of the Leupold scopes with the P5 mil knobs and scopes with the same size CDS knob as the P5.
Manufacturer: Leupold Custom Shop
BDC Calibration: 308 168gr Sierra Match King @ 2650 fps
Scope: Any Leupold scope with the P5 mil knobs such as the VX-Freedom AR 3-9x40mm, VX-Freedom CDS 4-12x40mm, VX-R Patrol 3-9x40mm, etc.