"I saw (the bulletproof) backpacks starting to sell and I thought that's a good product, but it wouldn't have helped Parkland (High School) because (the shooter) used a rifle," said Miller.
After retiring from the blast business, he got to work and made it his top priority.
"It gets elastic when the bullet hits, so you get some deformation and de-lamination with enough hits. It's how it disperses the energy," he explains. "It spreads it out and slows it down."
The whole point, he said, is for children to carry it just like any other book inside their backpack, or if it comes down to it, use it for protection.
"Hold it out and get as small as possible behind it," he showed us as the device is used as a shield.
The Safety-Book costs about $500 and Miller said he's also offering payment plans, even for schools.
"It's all plastic, basically. It's hard. It's dense. It gets elastic when the bullet hits," explained Miller.
Though he knows it's not a 100 percent guarantee, he said it could give your child a chance at survival.
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Bulletproof and clear backpacks among back-to-school options