Is the hood part 5mm or 3 mm?
JOE G Short answer: Yes. 5 for the hood, 3 for the vest.
Long answer: My first answer didn't seem like the right answer so I went out to the shop and go my micrometer. I doubled the hood and measured it...got 9.7mm and just under 6mm for the vest body doubled. The foam is kind of squishy, so my micrometer numbers are not accurate, I'm sure. 5/3 are the correct numbers.
JOE G I own the hooded vest and the hood and vest feel like the same thickness to me.