Rough Belts are blue internally and a sold in pairs. They are 180 grit. This grade of belt is designed to profile damaged and badly chipped knives. Because these belts remove a lot of metal they should be used with caution. Continually check the knife edge for overheating. Extremely hard wearing and long lasting, these belts are made from aluminium-oxide.
Nirey Replacement Belts Rough Pair