These are great sanding sticks and the assortment is so useful. I bought the assorted pack to try the sticks. You get a 100, 180, 240, 320, 400, 600, and 800 grit stick. They are tapered so you can us the small end or the big end. These have become my go to sticks. I plan on get the individual packs so I have more of each one. You can use them wet or dry and they clean out with ease. I can't say how long they will last, since I have only had them for less than a month, but they are holding up really great I used the on about 3 models so far.