Seven-year-old Liam Porter has something in common with "Star Wars" hero Luke Skywalker -- a new prosthetic arm. Liam was surprised with the arm by an all-volunteer team that makes 3D-printed prosthetics for kids for free.The space-aged prosthetic is modeled after Imperial Clone Troopers in Star Wars."Liam wants it made clear it is a Clone Trooper not a Storm Trooper arm," Liam's mother, Ryan Porter, told ABC News Clone Troopers are the good guys; it's the Storm Troopers yo have to worry about.The arm took about three months to make and cost about $300. It's lighter and easier to use than his old, traditional prosthesis.Liam, who lives in Augusta, Georgia, was born without the lower part of his left arm.Members of the 501st Georgia Garrison, a group of people that dress up as "Star Wars" troopers, surprised Liam with his new arm at a ceremony at a local movie theater."He was actually speechless, which for him is a rarity," Liam's mom said.In it's first year, E-nable, the network of volunteers that makes the prosthetics, gave away more than 700 arms and hands.