Chalk Mountain Brushes 3 Pack 45 Degree Multipurpose Medium Grit Angled Sanding Sponge Block. Use Wet or Dry Rinse and Reuse.

I'm not sure why, but these sanding blocks are the durable I've ever used. The versions from my local big box home center last 1/10th as long (that isn't an exaggeration).

have only used briefly - we shall see how long it lasts

Does a great job of sanding!

This product is just ok. They are cheap but worn off very quickly. The size of them make it arkward to hold. I will stick with 3m next time.

These are great ! I plan on ordering more.

excellent