clothing. Some holsters, such as ankle holsters, have integrated support. Other holsters may fit inside a pocket, to add stability and protection to the handgun, keeping it more reliably secure and accessible than if it were in the pocket alone. Holsters are generally worn in a location where they can be readily accessible. Common locations are: at the waist (outside (OWB) or inside (IWB) the waistband), behind the back (small of back (SOB), at the ankle, at the chest (in an elastic belly band or shoulder holster), or on the upper thigh. Holsters are sometimes contained in an external bag, such as a purse or fanny pack. Materials Since holsters are typically made from fairly stiff yet tough materials, there are a limited number of common choices. The traditional material, particularly for handgun holsters, is leather. It has an attractive appearance and can be dyed in many colors and/or embossed with elaborate designs for cosmetic reasons. Ballistic nylon is another common fabric for holsters, as it is stiff, wear resistant, and thick enough to provide protection from gun shots and bullets. Molded plastics, such as Kydex, are also popular, due to their low cost and robustness. Common types and styles Holster designs for firearms cover a wide range of shapes, materials, and retention/release mechanisms, from simple leather pouches hanging from a belt to highly protective holsters with flaps that cover the entire handgun, to highly adjustable competition holsters that hold the handgun at a precise position and release instantly when activated. The wide range of types indicates the highly varied circumstances in which holsters are used, and the varying preferences of the users. Categories by use Holsters can be divided into four broad categories by use: duty holsters, worn by uniformed law enforcement and peace officers and security personnel; tactical holsters, worn by military, security, and law enforcement personnel in certain situations; concealment holsters, worn by plainclothes peace officers and private persons; and sporting holsters, worn for shooting sports and hunting. Duty holsters are designed to be carried openly, so concealment is not an issue, but retention and appearance are. Duty holsters can be made of leather, nylon, or plastic; they are designed to be attached to a duty belt, and worn on the dominant side. Duty holsters are generally only found for service and compact size handguns as opposed to small subcompact handguns as these are generally only used