They were built of substances meant to mimic biological materials and had radiation sensors embedded throughout the torso.

WSJ: Scientists Find Safer Ways to Test Medical Procedures

Other watches incorporate ultraviolet radiation sensors and satellite-positioning systems.

ECONOMIST: MONITOR

Those little metal discs supplement the internal sensors, including functionality for radiation, heat, chemical and climate sensing.

ENGADGET: Node modular iOS sensor hands-on Hands-on

Chemical and biological sensors already in place on the National Mall will be supplemented with radiological detection equipment, including radiation pagers on the belts of some law enforcement officers.

CNN: Security at record high for WWII Memorial ceremony