The MD1122 UDT Life Preserver is intended for use as emergency equipment by underwater demolition teams. Provides a minimum of 19 lbs. buoyancy when inflated. These single Co2 cartridge vests were used by SEAL and UDT teams in Vietnam to provide buoyancy during waterborne missions. They were hot in use when worn as a collar so would often be worn under the arm until needed. These UDT Vests would also be used by Army Special Forces for waterborne operations.