What's the origin of this helmet?

Posted by rexching@reddit | mythbusters | View on Reddit | 5 comments

What's the origin of this helmet?

I've seen Adam wearing it in this portrait, seen it a couple of times on the TV show in the background, and I believe Heather Joseph-Witham wore it in one of the episodes.
I just think the style and cartoonish large size is delightful, and would love to own one myself!