This variation is generally easy to remove with the application of simple tension to release the bead. As the gauge thickens or ring diameter decreases, higher amounts of tension are needed to open the ring and in some cases ring expanding pliers may be needed. Other shapes and variations may be seen. Barbells are often used in nasal, large-bore ear piercings, eyebrows, and tongue piercings. Barbells are straight or curved, some into half-moons or nearly circular.
Straight barbells are straight rods with balls threaded onto each end.
A circular barbell is a heavier barbell curved into approximately a three-quarter circle. A fourth variation is called a slave, banger or captive barbell and has a CBR attached to one or both ends of the barbell. Barbells in complex shapes and with charms instead of balls are also common. Labret studs and L-shaped fishtail labrets are used in cheek, lip and labret piercings. Labret studs are barbells that have a small thin disc soldered in place of the ball on one end.