The 4mm toms do not have re-rings. Thats...crazy. I've never heard of shells that thin without reinforcement rings. Ever.
Maybe since they're 6 ply, that's enough to prevent warping? I dunno.
The bass is 24x18. Not a fan. The rack is 12x10, also not a fan.
I like how they sound though...nice and open as you would expect with thin shells. They sing nicely even at low volumes like he demonstrates in the video.