Derek Williams, director of sales and marketing for Amendment II, said Wednesday that the Salt Lake City-based firm has seen “incredible demand” for its pint-sized products that feature lightweight armor called RynoHide.

“We’ve seen incredible demand, sales have gone up 500 percent for those particular products,” Williams said. “It’s just gone through the roof.”

The backpacks, which retail for as little as $300, will stop a bullet fired from a .357 Magnum and feature an armor component that weighs just 10 ounces, Williams said. He declined to discuss specific sales figures.