Optics:
Complex, high light gathering optical system for a wide field of view with maximum edge-to-edge sharpness.
Nitrogen purged to revent fogging
Microstructure grooves to prevent residual reflections inside the tube for bright, contrasty images, even with backlighting
Reticle
Centered reticle in the 1st image plane (objective image plane) with patented zero setting system for precision adjustment of the point of impact without the use of tools.
And for the PH 4-16x50 and PH 6-24x50 the reticle is in the 2nd image plane (ocular image plane).
Quadratic adjustment area for full edge-to-edge ranging.
Robustness
Totally dust proof and waterproof, even without turret cap