S19. It's made all in one piece in a process like a bike helmet (but it's not one hit and gone like a bike helmet), and as a result it's really, really light. 300 grams is what I heard. They do have an adjustment mechanism that's a lot like a bike helmet, but they don't adjust a lot.
And it's also crazy stiff, like gabe said. Easton is hyping it as the most protective on the market as well as a revolutionary advance in helmet tech.
If you're wondering why so bike like, Easton is a part of Easton-Bell sports. Bell is a very big name in bike helmets. They also own Riddell, which has the NFL helmet contract.
Funny, that's not event the S19 that Mayers is wearing, it's the S9 (you can tell by the gray foam with holes in it in the front air vents.) Also, the announcer identifies it as an 517, which I know is a typo but come on.
They did a short feature on this during the Caps game the other night as well. They said it was unbelievably light and constructed much like a bicycle helmet.
I dont know why some are considering it dusty, seems to me that any advance in a helmet is a good thing. I was wondering the other day why helmets have seemed to not change in many years with all the other advancements out there. You're head is the most important part of your body to protect, anything that can make it more comfortable and kept safer is a good thing imo.