3M(TM) Softback Sanding Sponges are coated with aluminum oxide mineral. Each grade uses a range of mineral sizes. Fine ranges from grade 320 to 400.
- Aluminum oxide abrasive offers a long life and fast cut
- Waterproof bonding system allows for either wet or dry sanding applications
- Sponges are made for hand sanding
- Versatile sanding sponges work on many surface materials