Israel’s NeoMare is developing a wristband that inflates on command, potentially saving dozens of Israelis from drowning every year. NeoMare’s LifSsaver armband contains a chemical that inflates an 8-liter floatation balloon, to become a personal buoy if there is a danger of drowning.
https://www.youtube.com/watch?v=_XWM9x7WNDw