The Enhanced Magazine Release-Continuous Serrations features a slightly curved button surface to fit the natural curvature of your finger. The form fitting curve, along with horizontal serrations, create a self-centering surface that inhibits the finger's vertical movements. The EMR-HC has an uninterrupted surface and serrations, its taller profile makes it easier to press and is only 0.04 taller than the factory magazine release button. When installed, the EMR-HC has a 0.08 protrusion above the mag release button fence on most forged receivers. Due to the EMR-HC's installed height which protrudes 0.08"" over the mag release fence when installed (only 0.06" or Mfg: Forward Controls Design