These plain bearings are used on some band saws to guide the blade. While dedicated rollers would be a better choice for this purpose, they are similar to the originals on my relatively inexpensive saw. They last exactly the same length of time, which isn't long at all. Over time, the side seals loosen, sawdust, resin and the like clog them and they fail. Using a bandsaw is more of a test for bearings than using a skate. But they're cheap and come in packs of ten. Just keep an eye on them, try to blow the dust off and treat them with real oil and not lighter stuff like WD40 and it's an economical way to keep your saw running. Just replace them as soon as they fail. Of course, for commercial use, an upgrade to the guides will suffice, but for my home use so far these wheels are working well. Not a skater, but these bearings look and feel accurate. There are exotic ceramics that I believe are more suitable for competition. It would be interesting to see how they hold up on the saw. I only took off one star because I think the shield should last longer.