We really like these sanding sponges as they are suitable for so many applications, being particularly superb for harder surfaces such as metals, paints and laquers, as well as plastics, Corian, composites and fillers / primers. They are made of specially adapted aluminium oxide which reduces clogging but has a very long life. If any abrasive can be described as a super abrasive in the truest sense of the word, then it is this. As there is such a wide grit range, these sponges are great for many finishes. The sponge back helps you when sanding profiles or contours so that you are far less likely to sand through. For the automotive users, the course to medium grits are good for sanding fillers and primers where wet and dry on a rubbing block is either inacessible or runs the risk of rubbing through. The finer grades are good for preparing primer for the top coat, or even denibbing areas before final polishing. The sponges can be used either wet or dry. Corian, carbon fibre and glass fibre gel coats are also easily sanded with this product, either for stock removal, or for going through the finishing processes. The full roll is in a protective dispenser box to enable pads to be easily torn off, and has 200 sheets on it, perforated such that the sanding face is perfectly cut, leaving no rough edges that might spoil or scratch the finish you are looking to acheive.