In Water Heater Rocket (s5), what kind of helmet is Adam wearing?

Posted by Snobolski@reddit | mythbusters | View on Reddit | 6 comments

During the Water Heater Rocket in S5, while they're in the "bunker" waiting for it to blow, Adam is wearing a helmet or head cover that appears to be soft but with hard shells in the front and back, leaving the sides and part of the top soft. And either has integrated ear-muff headphones, or he's wearing headphones over it. In this YouTube clip he's wearing it around 1:26: https://www.youtube.com/watch?v=rGWmONHipVo Just wondering what kind of helmet that is. "Easy" google searching doesn't turn up anything...