This Commercial Item Description covers the requirements for Layer 1- Silk / Lightweight Undershirt fabricated in 100% polyester Polartec ® PowerdryTM style 9023 plaited jersey knit that dimensionally wicks moisture/perspiration away from the body. The undershirt is intended for wear by male and female military
personnel of the Department of Defense as an insulation layer of the Extended Cold Weather Clothing System (ECWCS).