Prior to 1943 the most common sweater worn by G.I.s was a v-neck. When what would be known as the M1943 Combat Uniform was developed a new high neck (5 button) sweater was an integral part of it. The new sweater was especially popular because of its warm high neck with five button closure which allowed the wearer to open up the throat area if he got too warm. In addition to the Army issue v-neck and high neck sweaters there were large numbers of home made and Red Cross made sleeveless sweater vests delivered to the troops.
All sweaters were 100% wool and colors varied from a light olive drab to a darker brownish green. The Army issue types are on the thin side and the ribbed weaves are very tight. The weave in the body and sleeves of both sweaters transitions into waistbands and cuffs with much larger ribbing that gathers slightly to seal out the cold. The neck and throat of the high neck sweater is an especially tight and soft weave. Contract labels are always sewn into the back of the neck but it is rare to find one intact; usually only the stitching that held the label in place remains.
Modern 5 button look alikes are not acceptable.