The woolen cap, known officially as the "Cap, Wool, Knit, M1941" is Radar's signature headgear on M*A*S*H. Known commonly among soldiers as the jeep cap or sometimes as a beanie, the cap was a standard uniform item issued from 1942 onwards to US army enlisted men. It was made of wool with short visor in front and cuffs which could be folded down to cover the ears in cold weather. It was designed to be worn underneath the helmet for added padding and warmth but could also be worn on its own, as Radar always did.