Sold as a single unit. Replacement black Shell for pre-2015 Pro model (Not XR3 model), (compare image before buying).  It is advisable that both the upper or/and both lower shells are replaced at the same time to prevent the other having more usage time, therefore cracking under pressure. Can be used in a combination with XR3 Shell H at the bottom. Store all spares in the KJ Bag with your boots (available separatley). Clamps are not available for this Shell.