After struggling through the brush of the thick jungle in Mission-Oriented Protective Posture response level 4 (MOPP-4) gear, Sergeant Mosser of 3D RECON BN, 3D MAR DIV, Okinawa, Japan, sucks down some refreshing water through his M40 Chemical Biological Mask. Water is very necessary when dealing with Nuclear, Biological, Chemical (NBC) conditions, especially in the heat when wearing MOPP gear can easily cause heat exhaustion. Third Reconnisiance Battalion participated in a training exercise that tests the unit's ability to react during a real world NBC threat