U.S. Navy Petty Officer 2nd Class Adalbert Guiterrez sits in a gas chamber with equipment to detect if his mask has a proper seal aboard the aircraft carrier USS Ronald Reagan in Yokosuka, Japan, Jan. 26, 2016. His mask is designed to withstand chemical, biological and radiological threats. The Reagan provides a combat-ready force to protect and defend the maritime interests of the United States and its allies and partners in the Indo-Asia-Pacific region. U.S. Navy photo by Petty Officer 3rd Class Nathan Burke