MERIWOOL Men s Merino Wool Midweight Baselayer Crew - Choose your Size Color Black Medium

Q: What percentage of wool are these items

In spite the retailer claim, it is not 100% merino wool. I arranged a burn test and a microscopy: the shirt made of merino wool + cotton fibers (in lesser degree). I'd bet 95% merino + 5% cotton. All materials give "natural" sources in burn test.

Q: What is the sleeve length in inches for L and XL?

I don't have the large but the extra large sleeve length from the outside shoulder seem to the cuff is 25 inches and the inside seem from the armpit to the cuff is 21 inches.