Tunnel/Flesh Tunnel/Eyelet - is a hollow, tube-shaped plug. You can see directly through a tunnel for a stretched or scalpelled piercing. However, the smaller the gauge the smaller the effect to see through the plug becomes. A person may choose to wear flesh tunnels instead of flesh plugs because they weigh less; at higher gauges, the weight difference increases. Flesh tunnels may be worn with a captive bead ring or other object passed through them.
Straight Taper - is a straight piece either steel or acrylic that is small on one side and larger on the other. When you insert a taper it will increase the size of your piercing. O-rings are generally included to keep your lobe at the desired area on the taper and allowing you to slide to a larger part when ready.
Spiral Taper/Crescents/Buffalo Tapers - can be used as both jewelry and a stretching taper. Similar to straight tapers but are a curved or spiral style. Buffalo Tapers/crescents are slightly different in that they are crescent moon shaped and have a tapered end on either side. Spirals are obviously spiral shaped and have 2 tapered ends but are more ornamental than a stretching tool.
Ear Hanger - similar to spiral tapers, ear hangers are mostly ornamental in use. They are small on one side and larger on the other like straight tapers but the larger side will have an decorative feature attached instead of the standard o-ring on a straight taper.
Screw Fit - is a tunnel or plug that has threaded ends that the flared part will be removed/unscrewed to allow for ease in insertion. (This can be better for certain plug wearers. Double flared ends can be a challenge for the wearer to get in especially if they are at a new size/gauge.) The threaded ends can be internally threaded or externally threaded (see below for definition of both).
Double Flare - is a plug that has flares on both ends (the flares are actually slightly larger than the actual center). Double flare plugs are totally fine to wear but they can sometimes be hard to get in (especially on sizes under 0 gauge). This is why it is important to differentiate between double flare and single flare - it can determine if the customer can wear the item or not. Double flares should only be worn in well healed stretchy lobes, as the flare is much bigger than the wearable, and lobes need to stretch further to get them in. (No o-rings used for this style)
Saddle Plugs - flares have a smooth curved flare to join onto the wearable area. Not too far off from a double flare style but the flared ends are not as abrupt and often times slightly smaller making for an easier insertion.
Single Flare - is a plug that flares on ONLY one end (the flares are actually slightly larger than the actual center). An o-ring is generally on the other side to keep the plug in. This is ideal for people new to their size. Inserting a single flare plug is much easier when your lobes still needs some time to adjust.
No Flare/Straight Plug - is a plug that most likely has a removable band on each side to keep it in your ear. There are no flared ends on either end on this style of plug/tunnel. This is also an ideal style for people new to their size because there are not flared ends.