Robert Downey Jr., also known as super hero Iron Man, came to the rescue of a very lucky seven-year-old boy named Alex Pring.

Downey worked with Enabling The Future, which helps distribute mechanical prostheses around the world for children in need, to personally deliver an Iron Man-themed bionic arm the boy, who was born without most of his right arm.

The project, led by Albert Manero, aims to make low-cost 3D-printed arms for the disabled. Limbitless' first arm — made for Alex — cost less than $350 US in materials, much cheaper than the $40,000 price tag of some prosthetics. The arm was delivered to Alex at no cost.

"Had the absolute privilege of presenting a brand spanking new 3D-printed bionic Iron Man arm to Alex, the most dapper 7-year-old I've ever met," Downey said on Facebook Thursday.

This isn't the first time Enabling The Future projects has changed a child's life. In January, a Storm Trooper arm presented by Vader himself was delivered to a seven-year-old Augusta, Ga., boy named Liam Porter.

Check out the video.