Description With a high ceramic content, closed-coat abrasive grain and heavy polyester backing, our Nitro EXTREME Ceramic Discs are a very high-quality product with superior performance and durability to anything on the market. Being closed coat the material is very aggressive and therefore offers faster stock removal, particularly on hard woods. The strong polyester cloth backing is tear-resistant and the self-sharpening feature of the ceramic grains provides a consistent finish throughout the life of the disc. Offering the best performance while at a very attractive price, we find this to be a very popular product with our customers. The feedback which we have had is that these belts can last up to 4 times longer than zirconia discs, depending on the type and porosity of the wood floor.