Center plr reinf nut plate. Left. Right. A solid metal or plastic block with a threaded hole in the center which is used to tighten or adjust the B Pillar Reinforcement. A solid metal or plastic block with a threaded hole in the center which is used to tighten or adjust the Quarter Panel. Plate for door lock striker. Body B - Pillar Reinforcement. Center Pillar REINFORCED. Door Lock Striker. Quarter. Uniside. Included with: Center Pillar Reinforcement, Inner center Pillar, Quarter Panel, Reinforcement Panel, Uniside Panel.