What's the difference between P-40 Classic Gen. 2 and All-terrain Gen. 2 tactical pants?

The most prominent differences between the Classic Gen.2 and the All-Terrain Gen.2 models are these:

CORDURA® reinforcements.

Unlike the P-40 Classic Gen.2, the P-40 All-Terrain Gen.2 features CORDURA® reinforcements in places where damaging abrasion is usually a problem. These abrasion-prone locations include belt loops, pocket edges, and instep. Since the P-40 Classic Gen.2 pants come without additional reinforcements they are lighter and more breathable.

Pocket closure system.

Generally, the pocket closure system of the P-40 Classic Gen.2 is a Velcro® strip, whereas the All-Terrain model employs a zipper.

Number of pockets.

The All-Terrain model comes with more pockets—meaning you can carry additional items. For example, there is a small pocket on the thigh (suitable for stowing a knife) and a smaller, strap-secured gear pocket on top of the side pocket.

Boot hooks.

Affixed to the hem at the bottom of each P-40 All-Terrain Gen.2 leg are boot hooks that connect the pants to your footwear. The hooks prevent the pants from riding up your leg as you walk, run, sit, or crouch.