Coastal Pet Chrome-Plated Extra Links for Dog Prong Training Collars | Fine 2.0mm | 3-Count per Pack (1-Pack) These Extra Links for Dog Prong Training Collars may be added or removed for proper fit. 3-Links per Pack. Fine 2.0mm Thickness. (1-Pack) Chrome-Plated for maximum strength and durability It will not tarnish, rust or break. Coastal Pet Item Number 05591H G200