The generally available consumer version RescueStreamer is day use only. They have developed a version of the SEE/RESCUE with some IR and retroreflective material attached for military use. That would reflect back IR light to its source if you shined a light on it and were wearing night vision or IR goggles. Some reports that this version doesn't float as well due to the weight of the material, but haven't tested it myself. See: http://www.seerescue.com/IRfeatures.htm<br>