RCP (Rail Cover, Picatinny) is a 1913 / Picatinny rails panel with the AA (All Angles), or dimpled texture. We use the dimpled surface on applications where it makes sense: bolt catches, magazine release buttons. The AA, or dimpled surface, is our idea of cross hatching, same end but different means. Briefly, the AA (all angles) surface offers equal traction and friction regardless of the angle of approach, i.e. the angle at which the hand holds it, or the angle of the finger that presses the control. Serrations can be very effective as long as the movement they're tasked to reduce / mitigate is perpendicular, or 90 degrees to the serrations, serrations start to lose their effectiveness when the angle of approach is 45 degrees or greater. Cross hatching has no such limitations, neither does the AA surface.