This is ATF's new reproduction of the US Army's "od flannel shirt", standard issue for all of WWII. They have made a run of shirts using 100% cotton flannel rather than the wool blend of the originals. Visually, they look nearly identical- but when it comes to care and, above all, comfort they are night and day. These are the M37 Pattern with the placket and structured collar so for a sharper appearance when wearing neckties.This fabric looks like the wool cloth used on WWII shirts- far less awful than the 80% polyester Sturm shirts which are worn by hundreds of reenactors that glisten in the sun. They are a life saver for summer events and can be machine washed.Sized like modern flannel shirts- S, M, L, XL, and XXL.