Israel’s Masada-Armour has developed a unique backpack that transforms into a bulletproof vest in under two seconds. It was designed to protect children against the threat of school shootings. The basic 3kg version stops handgun bullets and the upgraded 4.2kg version blocks rifle fire.

http://www.israelhayom.com/2018/09/14/israeli-company-fashions-bulletproof-backpack-to-protect-against-school-shootings/

https://www.masada-armour.com/bullet-proof-backpack