These ( and others ) have been accumulating in the headwear bin. A lone Multicam in a sea of Woodland, 3 usual NWU III, and 2 US Navy A2 cold weather covers.
USN used a series of A2 cold weather clothing in the late 60s through early 80s, mostly for shipboard use . The covers resemble M51 " patrol caps ", but are more heavily insulated.