They can also be used as a small, strong link between different lines.

Anti-glare black finish reduces visibility under water.
Extra strong and completely reliable.
Seamless manufacture for good knot strength.
10 rings per packet.
Product Outside Diameter 
COVERT RIG RINGS EXTRA SMALL ANTI GLARE 2.5mm FWRR1
COVERT RIG RINGS SMALL ANTI GLARE 3mm FWRR2
COVERT RIG RINGS LARGE ANTI GLARE 4mm FWRR3
COVERT RIG RINGS EXTRA LARGE ANTI GLARE 4.4mm FWRR4
COVERT RIG RINGS OVAL ANTI GLARE 4.5mm (length) FWRRO
COVERT RIG RINGS LARGE OVAL ANTI GLARE 6mm (length) FWRROL