These sanding discs are a lifesaver for anyone in the industrial and SCIENTIFIC fields! Through trial and error, i found that these were the most durable and effective sanding discs I have ever used! They fit perfectly onto my sander and clung on tight, allowing me to sand down even the toughest materials with ease. The 25 pack is also a great value for the price. The only downside is that I wish they were available in a larger pack size. Overall, I highly recommend these cling fit sanding discs for anyone looking for a high-quality sanding solution in industrial power tools! .