I contacted the vendor with some questions about waterproofness, breathability and sizing - their reply:
Terri to me,
About our tyvek jackets -
They are water and wind resistant but they are not noted for their breathability. The jackets are made of Dupont Tyvek, the same product they wrap houses in before adding the siding.
Here are the approximate size dimensions-
L - armpit to armpit 25", waist 24 1/2", length 27", sleeve length 25", for chest size 38 - 41"
XL - armpit to armpit 25 1/2", waist 25 1/2", length 28", sleeve length 25", for chest size 42 - 45
XXL - armpit to armpit 27", waist 29", length 28", sleeve length 25", for chest size 46 - 49
The XXL jackets have mesh fabric at the side seams to allow for the bigger size.
The waist size is from seam to seam, not circumference, so just double it. Sleeve length is measured from shoulder seam (where the sleeve is sewn in) down to the hem at the wrist.
Hope that answers your questions.
Have a great day,
Leslie Jordan, Inc.
ps. I measured 3 jackets your way. From the neck/hood seam down to the end of the sleeve.
L - 33 1/4 "
XL - 34 1/4 "
XXL - 34 3/4 "
Hope that answers your question.