These extra links are individual sections of welded steel chain designed to attach to a Titan prong training collar. Each pack contains three links that can be added to extend the collar or removed to shorten it, allowing the chain to be sized to a dog's neck. The chain is chrome plated and constructed to resist tarnishing, rusting and breaking under regular training use. Link ends are blunt so they can be opened and closed by hand to connect to the existing prong chain without additional tools. The links are sold separately from the collar itself and are matched to a specific gauge so they fit collars of the same thickness. As with any chain training collar, this accessory is meant for supervised training sessions rather than for tying a dog out unattended.