Robert Downey Jr. plays a superhero on the silver screen, delighting audiences worldwide as Tony Stark in the Iron Man and Avengers films. But just like his Avengers counterparts Chris Pratt and Chris Evans, Robert occasionally use his superhero powers to bring joy to children in need.

In this case, Downey Jr. teamed up with Microsoft to bring 7-year-old Alex a 3D-printed bionic arm courtesy Limbitless Solutions.

Downey and Alex compared their arms, concluding that Alex’s was better because his light actually worked. While a working light is nice, a fully functioning 3D-printed arm (available copyright-free for anyone with access to a 3D printer) for a child born with a partially developed right arm is what really makes Alex’s arm more super.

arm comparison