A plug (sometimes earplug or earspool), in the context of body modification, is a short, cylindrical piece of jewelry commonly worn in larger-gauge body piercings. Modern western plugs are also called flesh tunnels. Because of their size—which is often substantially thicker than a standard metal earring—plugs can be made out of almost any material. Acrylic glass, metal, wood, bone, stone, horn, glass, silicone or porcelain are all potential plug materials.
Plugs are commonly, and have historically, been worn in the ears. They can, however, be inserted into any piercing.
In order for a plug to stay put within a piercing, the ends of its cylindrical shape are often "flared out," or the plug is fastened in place by o-rings. Combinations of these two methods may also be used.
- A double-flared (or saddle) plug, flares outward at both ends, and is thinner towards the middle. No o-rings are needed to keep the plug in the piercing, but the fistula needs to be wide enough to accommodate the flare when the plug is initially put in.
- A single flared plug has one flared end, usually worn on the front of the piercing, and one end with no flare. The no flare end is held in place by an o-ring and may or may not be grooved. These plugs give the aesthetic of double-flared plugs without requiring that the wearer's fistulas be large enough to accommodate flares.
- A straight plug (or no-flare plug) is a typical-looking cylinder, without flares, and is kept in place by sliding o-rings against both ends of the plug. A grooved plug is a variation on the straight plug, with grooves carved in the material to hold the o-rings snug.