Full-frame 4D Focus: Innovative Hybrid Phase Detection AF system with accurate 79 hybrid cross AF points[i] enabled by 79-point dedicated and 399-point focal-plane AF sensors and continuous shooting at up to 12fps[ii]
In a nutshell, this patented handheld device uses compressed gas to produce perfect air rings. The idea is that you simply 'tag' your buddy with these air rings to attract their attention in low visibility.
I am sure that we have all told a positively blue child who is shaking like a leaf “that now is a good time to climb out of the water and get dry”. And to hear the emphatic response through chattering teeth, “but I’m not cold”!