In a recent interview, Bryce Huff explains why he ended his NFL career at age 27 and turned down a lot of money.

Bryce Huff’s retirement came as a surprise. The pass rusher announced his retirement in March at the age of just 27.

His rise in the NFL had been rapid: Six years ago, he entered the NFL as an undrafted free agent. Two years ago, he signed a three-year, $51 million contract with the Philadelphia Eagles. A year ago, he was traded to the San Francisco 49ers.

Why would someone like him end his career and forgo so much money? It was a family decision that Huff and his older brother Jordan had been considering for some time. “I feel like we’re going to save a lot of lives and protect a lot of companies,” Huff told “The Athletic.”

The brothers have set out to tackle the problem of fire risks posed by lithium-ion batteries. Huff, who celebrated his 28th birthday in April, has been building the company Naberstone for two and a half years now.

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“Things are going well, but we’re still in the very early stages,” he said. Naberstone, which he has self-funded, currently employs six people and has already secured a “pretty big” client. According to Huff and engineer Nik Tacker, the company is also in talks about additional agreements, including with the U.S. military, a major waste recycling company, and potential partners in Europe and Asia.

Huff is convinced that Naberstone can help solve a growing problem: “These days, more and more things contain batteries—from cars to tools to bicycles, practically everywhere. The biggest risk with batteries is that they can catch fire if they’re damaged, malfunction, or short-circuit. First, a single battery cell catches fire—and then it spreads like a chain reaction throughout the entire battery.”

The former NFL player and his brother now have a solution that isn’t available anywhere else on the market. Ending his NFL career to pursue this wasn’t a problem for him. “You can only play until your thirties anyway,” Huff said. Plus, the knowledge he gained from his mechanical engineering studies is now coming in handy.

He didn’t complete his degree back then because one of his favorite professors was laid off due to budget cuts. Huff then shifted his focus to American football.

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“When I went into the NFL, I couldn’t really put my love of engineering to good use,” he said. “But now I feel that, since we work with engineers every day, it’s just as good as being an engineer myself.”

Now others have to chase after quarterbacks.