Famous actor Robert Downey Jr., the star of Iron Man movies, joined forces with Albert Manero, a doctoral student in mechanical engineering at the University of Central Florida, to make an adorable 7-year-old boy very happy.

Young Alex, whom Robert Downey Jr. described as the “most dapper 7-year-old” he has ever met, was born with a partially developed arm. Now, thanks to volunteer group Limbitless Solutions, run by Manero, that builds and donates low-cost 3D-printed bionic limbs to kids around the world, he has his own “Iron Man”-themed prosthetic limb.

The arm, which cost just $350 in materials, was delivered by Tony Stark himself. Watch the video below and prepare to be moved!