A seven-year-old baseball fan with a 3D-printed hand is throwing out the first pitch of World Series Game 4

Hailey Dawson is already a veteran of tossing the ceremonial first pitch at the ripe old age of seven. She’s got two Major League games under her belt and is about to add a third, with her biggest audience yet, as she kicks off Game 4 of the World Series in Houston.

Dawson is in the midst of a 30-ballpark tour, throwing the first pitch for every MLB team, with the aid of a 3D-printed prosthetic hand created by a research team at the University of Nevada, Las Vegas. Dawson was born with a rare condition called Poland Syndrome, which left her missing three fingers on her right hand

But prosthetics are traditionally extremely pricey, and many insurance plans won’t cover the $25,000+ to supply them for children, deeming them “unnecessary,” unlike a leg. Children quickly outgrow the devices and the cost starts to add up. It’s a hole in the healthcare system that has been tackled by a number of groups in the 3D-printing industry, including n.

But prosthetics are traditionally extremely pricey, and many insurance plans won’t cover the $25,000+ to supply them for children, deeming them “unnecessary,” unlike a leg. Children quickly outgrow the devices and the cost starts to add up. It’s a hole in the healthcare system that has been tackled by a number of groups in the 3D-printing industry, including not-for-profits like the Open Hand Project.

Using a 3D printer to create a customized 3D-printed hand or arm dramatically reduces the manufacturing cost and allows for much easier part swapping, should something be broken or its wearer just grows out of it.

Hailey’s mother, Yong, reached out to their local University, UNLV to ask if they’d be able to help create a custom prosthetic. Brendan O’Toole, chairman of the the school’s mechanical engineering department, obliged. “Additive manufacturing has made it possible to provide low-cost prosthetic devices for children like Hailey,” he tells TechCrunch. “We can now make a few measurements of a child’s hand, process them through our custom design tool that generates 37 CAD models in a few minutes, and then have printed parts ready the next day.”

O’Toole’s team got to work creating a hand on a Stratasys 3D printer. “That’s the beauty of 3D printing,” Stratasys’ Jesse Roitenberg told TechCrunch. “It’s not just printing the next rocket or the dashboard of a Ford. It’s being used to improve lives.”

It also offers kids the ability to customize their arms, like that Iron Man kid a few years ago, or, in Dawson’s case, the colors of the team she’s visiting. She’s getting a custom hand for tonight’s game as well, but UNLV’s not showing off whether it’s Dodger blue, Astros orange or something else a bit more neutral. First pitch airs tonight at  5:09 P.M. PT.

As for what 3D printing means for the future of prosthesis, “I believe with the movement that’s going on right now, prosthetic companies might be shaking in their boots,” says Roitenberg. “They need to be looking into these alternative ways to create the prosthetics that they have.”