The ACU patrol cap is a visor style, having a circular top crown with a two-piece inner crown lining forming a pocket between lining pieces.

USMC cold weather cap is not a replacement for the currently sustained USMC microfleece hardface cap but would be worn separately from the current cap when increased protection from wet and dry cold weather environments is needed.

The hood replaces combat vehicle crewman's hood as a component of ECWCS.

The ruff is an attachable component used with the extended cold weather parka.

The olive drab cotton field cap is a visor style with retractable earlaps lined with wool flannel, and grommets for ventilation. It was designed to be worn with the M-1943 field jacket. It could also be worn under the hood of that jacket and with the steel helmet and liner.

The olive drab pile field cap consists of a wind-resistant, water-repellent, poplin outer shell with a pile lining, a flexible visor, which can be worn up or down, and pile ear flaps with an drawcord closure. It was designed for wear in extreme cold.

The MQ-1 (Model Quartermaster 1) olive drab pile field cap is a modified version of the olive drab pile field cap. The pile lining of the original visor, which caused visual interference and forehead discomfort when the visor was lowered, was eliminated. The MQ-1 cap was adopted as the M-1951 pile field cap.

The M-1951 cotton field cap is a visor style with a circular top crown and retractable earlaps, and is a lightweight windproof item incorporating a very thin layer of insulation only in the earlaps. It was designed for ground troop wear in a range of cold-wet to hot environments.

The M-1951 pile field cap may be worn for both cold-dry and cold-wet conditions. The cap provides the best protection against the elements for weather colder than 0°F.

The M-1951 winter hood is worn attached to the coat for protection against the wind and snow as a component of the cold-wet uniform.

The M-1951 winter hood with fur ruff is worn attached to either the coat or the parka as a component of the cold-dry uniform. The hood may be worn over the cotton field cap or the pile field cap. The steel helmet is not normally used with the hood.

The M-65 cold weather insulating helmet liner cap is worn alone or as a liner for the helmet assembly. The earflaps are fasten under or over chin, at back of neck, or are folded up around the top with the touch-and-close fasteners crisscrossed in the front.

The M-65 extreme cold weather hood with fur ruff is an attachable component used with CW field coat, ECW parka, M1951 parka as a component of the cold/dry uniform.

The hardface micro fleece cap is intended for wear by male and female military personnel of the USMC in mountainous and cold weather environments.It will provide improved wind resistance, durability and water repellency when worn in intermediate to cold weather environments.It will be part of the Mountain/Cold Weather Clothing System and will ultimately replace/phase out the current micro fleece caps.

The lightweight protective hood is a fire-resistant, no-melt, no-drip head and face covering that provides the Soldier with protection from thermal threats and minimizes heat stress in hot-dry climates while providing limited heat retention in cool climates.

The FROG balaclava has a hinged face guard that allows wearer to expose face without having to remove helmet and balaclava. It is issued in light and mid weight FR materials for different seasons.

The hot weather field cap is a baseball-style cap made of olive green shade 106 polyester and rayon gabardine cloth, conforming to MIL-C-41820. It was intended for wear as a component of the hot weather field uniform and the OG-107 utility uniform.

The OG-507 hot weather cap is a baseball-style cap, with a visor and stiffner on the inside front, and was intended for wear as a component of the hot weather field uniform and the OG-507 utility uniform.

The knitted wool watch cap is intended for wear by Naval and Air Force personnel in cold environments.

The patrol cap, formerly called the battle dress uniform (BDU) cap, is a visor style with a circular crown and retractable earlaps, which is the same basic design as the M-1951 cotton field cap. It was intended for wear with the temperate battle dress uniform.

The hot weather patrol cap is a visor style with a circular crown and air vents. It was intended for wear with the hot weather battle dress uniform.

The microfleece cap is intended for wear as multipurpose lightweight head protection.

The hot weather sun hat is a lightweight, soft crowned model with a quilt-stitched brim and chin strap. The hat is lined with self material.

The FR anti-flash hood is intended to protect its user from transient and elevated air temperatures, resulting from the use of high explosive weapons, and is used with the FR anti-flash gloves.

The CVC hood is intended to provide combat vehicle crewmen protection against wind, cold and flame and also worn with the extended cold weather parka, and under the M-1 or PASGT helmet as a component of ECWCS (later replaced by extended cold weather balaclava hood).

The Lightweight Performance Hood (LPH) is a fire-resistant, no-melt, no-drip head and face covering that provides the Soldier with protection from thermal threats and minimizes heat stress in hot-dry climates while providing limited heat retention in cool climates.

Army specification 6-374.

Commercial item description A-A-50369 covers the requirements for a Cap, Knit (Watch) used by Navy personnel in cold environments.

Commercial item description A-A-55294 covers the requirements for a visor style cap that is intended for wear in hot weather environments by military personnel of the Department of the Army.

Commercial item description A-A-55312 covers the requirements for a visor style cap that is intended for wear in a temperate zone environment by military personnel.

Commercial item description A-A-59453 covers the requirements for a synthetic microfleece cap that is used as multi-purpose lightweight head protection.

Commercial item description A-A-59788 covers the requirements for a visor style patrol cap with inside pocket on crown of cap, intended for wear in all environments by military personnel of the Department of Army.

Military specification MIL-C-10869 covers the M-Q1 (Model Quartermaster 1) pile field cap.

Military specification MIL-C-16472 covers the requirements for a knitted wool watch cap.

Military specification MIL-C-1911 initially covered a cap made from olive drab shade 7 cotton poplin with flannel lined earlap.

Military specification MIL-C-1913 covers a cotton poplin, field cap with wool pile lined earflaps.

Military specification MIL-C-3000 initially covered a cap made of od-7 herringbone twill cloth, and then a cap made of og-107 cotton sateen cloth.

Military specification MIL-C-43225 covers a baseball-style cap made of dyed olive green shade 106 polyester and rayon gabardine cloth.

Military specification MIL-C-43549 covers a fully lined insulating helmet liner cap with adjustable forehead flap.

Military specification MIL-C-43724 initially covered a hot weather field cap made from olive green shade 106 polyester/rayon gabardine cloth, and then a hot weather cap made from olive green shade 507 polyester/cotton durable press material.

Military specification MIL-H-11023 covers a winter hood with fur ruff used with the coat or the parka.

Military specifcation MIL-H-11377 covers a hood for M-1951 field jacket.

Military specification MIL-H-43455 covers a hood with synthetic fur ruff.

Military specification MIL-H-43577 covers hats made of cotton material.

Military specification MIL-H-44105 initially covered a hat made of cotton/nylon twill material dyed in a 6-color camouflage desert pattern and then different types of hot weather sun hats.

Purchase description MC/PD 04-2011 SYSCOM covers the requirements for the U.S. Marine Corps cold weather cap.

Purchase description covers the requirements for the US Navy working uniform boonie cap in desert and woodland camouflage.