Twittern Buy O-LW98A Cap for HD D-FA 15-30mm F2.8 ED SDM WR - Overview Buy Description The PENTAX O-LW98A front lens cap is for use for the HD PENTAX-D FA 15-30mm F2.8 ED SDM WR lens. It helps to protect the front lens element from scratches, dust, and moisture when not in use.