Fit: Loose at true size. I feel this runs about half a size big like similarly sized items in the past. So S fits S-M. M fits M-L. L fits L-XL. XL fits XL-1X. 1X fits 1X -2X. 2X fits 2X-3X. If between sizes go smaller of the 2.
Model 1 is 5’8” and wearing Small. Model 2 is 5'10" and wearing size XL. I am also in XL.