The t-shirt shall have short sleeves, a crew neck collarette that shall finish 3/4 + 1/8 inch wide. The sleeve and bottom shall be hemmed approximately 3/4 inch from edge. All seams shall be overedged or cover stitched. The color shall be Olive Drab.

The underwear layer next to the skin acts as a moisture wicking layer and serves to draw moisture away from the skin, transferring it to the outer layers of the system.

Lightweight Cold Weather Underwear Set (LWCWUS) was developed to provide a moisture wicking, heat retentive, lightweight garment for moderate conditions not sufficiently cold for the polypropylene underwear.

The undershirt and drawers are designed to be worn next to skin by itself and to transfer moisture from the skin to the outside of the fabric where it spreads rapidly for quicker evaporation.

The shirt and drawers are designed to provide light insulation for use in mild climates as well as a base layer for colder climates, worn next to skin by itself or in conjunction with other levels (level I) for added insulation and to aid in the transfer of moisture.Fabric is slightly different than level I in that it provides extra warmth but still wicks moisture away from the skin to allow for quicker evaporation.

The LEP layer 1 silkweight undershirt and drawers are intended for wear as a moisture wicking layer of the ECWCS.

The LEP layer 2 midweight undershirt and drawers are intended for wear as an insulation layer of the ECWCS.

The M-1950 winter underwear serves as inner layer in cold-wet and cold-dry climate.

The M-65 cold weather underwear serves as inner layer in cold-wet and cold-dry climate.

The mid-weight FR grid fleece underwear is a flame resistant version of the polyester grid fleece underwear.It will provide improved moisture management, insulation and comfort when worn in intermediate to cold weather environments. In addition, it will provide Marines with FR protection when needed. The FR Grid Fleece can be worn as part of the Mountain Cold Weather Clothing System or Flame Resistant Organizational Gear (FROG).

The mid-weight grid fleece underwear is intended for wear by male and female military personnel of the USMC in mountainous and cold weather environments.It will provide improved moisture management, insulation and comfort when worn in intermediate to cold weather environments.It will be part of the Mountain/Cold Weather Clothing System and will replace the current polypropylene underwear set, and fleece pullover.

The FR next-to-skin underwear is a flame resistant version of the polyester silkweight underwear.It will provide improved moisture management and comfort when worn in intermediate to cold weather environments. In addition, it will provide Marines with FR protection when needed. The FR Silkweight Underwear can be worn as part of the Mountain Cold Weather Clothing System or Flame Resistant Organizational Gear (FROG).

The new next-to-skin underwear is intended for wear by male and female military personnel of the USMC in mountainous and cold weather environments.It will provide improved moisture management and comfort when worn in intermediate to cold weather environments.It will be part of the Mountain/Cold Weather Clothing System and will also replace the current lightweight CW underwear set.

The FREE system t-shirt and boxer briefs next-to-skin layer is constructed with a tri-blend of lenzing FR rayon fiber, wool, and nylon. This layer is extremely lightweight and breathable to allow high moisture movement and quick drying.

The FREE system undershirt and drawers base layer is constructed with a lightweight moisture wicking and breathable lycra mesh fabric made with DuPont Nomex fiber. This base layer provides maximum comfort and excellent recovery properties in hot climate, and can be worn under other layers like the mid-weight shirt and drawers for additional protection for cold weather.

In addition to being FR, this shirt has a mock neck design for added protection and also contains an antimicrobial property along with moisture management (wicking) capabilities.

Commercial item description A-A-55246 covers the technical requirements for polypropylene undershirt and drawers, components of ECWCS.

Military specification MIL-D-10212 covers M1950 winter drawers.

Military specification MIL-D-43261 covers men's cold weather wool/cotton drawers.

Military specification MIL-D-44165 covers polypropylene drawers used as a component of ECWCS.

Detail specification MIL-DTL-32620 covers a flame resistant (FR), lightweight, cold weather undershirt.

Detail specification MIL-DTL-32621 covers flame resistant, lightweight, cold weather drawers.

Detail spcification MIL-DTL-32624 covers flame resistant, mid-weight, cold weather drawers.

Detail specification MIL-DTL-32625 covers a flame resistant, mid-weight, cold weather pullover shirt.

Military specification MIL-U-10211 covers M1950 winter undershirt.

Military specification MIL-U-43262 covers men's cold weather, wool/cotton undershirts.

Military specification MIL-U-44164 covers a polypropylene undershirt used as a component of ECWCS.

Purchase description CR/PD 05-08 covers the requirements for a moisture-wicking t-shirt.

Purchase description GL/PD-06-01 covers the requirements for a lightweight undershirt, which serves as a layer of the GEN III ECWCS.

Purchase description GL/PD-06-02 covers the requirements for a synthetic grid fleece shirt, which serves as a layer of the GEN III ECWCS.

Purchase description GL/PD-06-14 covers the requirements for lightweight drawers, which serve as a layer of the GEN III ECWCS.

Purchase description GL/PD-06-15 covers the requirements for synthetic grid fleece drawers, which serve as a layer of the GEN III ECWCS.

Performance specification MC/PS 01-2015 SYSCOM prescribes the performance requirements and identifies verification procedures for the U.S. Marine Corps flame resistant lightweight cold weather underwear set undershirt.

Performance specification MC/PS 02-2015 SYSCOM prescribes the performance requirements and identifies verification procedures for the U.S. Marine Corps flame resistant lightweight cold weather underwear set drawers.

Performance specification MC/PS 03-2015 SYSCOM prescribes the performance requirements and identifies verification procedures for the US Marine Corps flame resistant midweight cold weather underwear set pullover shirt.

Performance specification MC/PS 03-2015 SYSCOM prescribes the performance requirements and identifies verification procedures for the US Marine Corps flame resistant midweight cold weather underwear set drawers.