Delta PSA sanding discs are designed to be durable and long lasting, and they will enhance the performance of your disc sander. These quality sanding discs attach to your sander with a pressure sensitive adhesive, allowing for an extra tight hold during sanding. Delta uses aluminum-oxide grains on their discs for improved life and performance. For the best results make sure to select the ideal grit for your needs. If you have any questions about which grit is right for you, feel free to email or call us.