An Israeli company says it has come up with a unique item to protect against school shootings — a bulletproof backpack that transforms into a bulletproof vest.

Masada-Armour says its backpack also deploys a protective vest in less than two seconds by flipping out an armoured plate from a concealed compartment. The standard protection claims to stop handgun bullets, upgraded versions can block rifle fire.

Co-owner Yair Rosenberg says the product, with its front and back protection, was designed to give schoolchildren defences. He says in an era when schools have become war zones, his company has seen increased interest in the product.

The basic version weighs 3kg and sells for US$500 ($763). The upgraded 4.2kg version costs US$750.