Picote Original Premium chain (12 mm shaft) with large heavy U carbide 7-ridge links - all sizesPicote Original Premium chain (12 mm shaft) with large heavy U carbide 7 ridge links all sizes Larger and heavier U carbide (7 ridge) links makes it stronger and faster than any other chain on the market. A versatile tool for cast iron pipes. For tough descaling, hard deposits and removing residual concrete or failed liner, including inconsistencies, wrinkles and remains.