rings can be used to make many kinds of rigs including the D- or the classic Blow Back . Rings can be used as an alternative to shrink tubing when slid on to the hook . rings are not only useful for carp fishing, they can be used for many types of fishing including Coarse fishing, Pike fishing and Catfish fishing.Extra high strength and carrion resistance.Simple design for easy operation.Carp Fishing Terminal Tackle.QTY: 100pcscolour: BlackMaterial: stainless steel Size: 4 ,External diameter: 7.6mm,Internal diameter: 5.0mm,Thickness: 1.2mmPackage Contents: 1 * fishing O Ring (100Pcs)Only the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.