Not sure, i think it's stainless.. it's a reverse replacement, the ball and socket are reversed.. i have almost full mobility which is amazing.. i still play drums 2+ hours every night. I crashed a mountain bike and my body made a sound like glass shattering.. i broke the ball/socket/arm to the elbow.. basically everything except my collar bone..
P.S. i don't see myself ever flying anywhere.. so shouldn't be an issue :)