BOSTON -- It's time for parents to make the annual trek to get back-to-school items, which usually includes jeans, jerseys and a few notebooks.

Boston television station WCVB reported Thursday that a couple of Boston men want parents to consider something else -- a bulletproof backpack.

"They have them with them on the floor, on their laps, on the bus. They always have a backpack," said Joe Curran, of My Child's Pack.

It started with the Columbine shooting in 1999. Curran and Mike Pelonzi said that they watched and worried for their own children. They had the idea to hide bulletproof material inside a backpack. They call it defensive action.

"If the kid has a backpack next to them, or under the desk, they can pick it up, the straps act as a handle and it becomes a shield," Curran said.

It's much lighter than a 15-pound police vest. After three years of experimenting, the backpacks that were tested by an outside lab ranked threat level two. It stops an assortment of bullets, including 9-millimeter hollow point bullets. The fathers researched school shootings from 1900 to this year.

They will sell for $175, but do the special book bags play upon paranoia when most schools are called safe?

"I want to keep my kid safe," Curran said. "I don't care what you do -- if you want to fight the good fight or fix the world's hurts, I can't help you, but my kids are going to be safe because of these backpacks."