sliding mirror closet doors replacement bottom rollers

I am afraid I can't narrow down what you need from this information alone. Can you show us a picture of your existing roller? That would help narrow things down a lot. Thanks.

We've seen this roller before. I'm afraid I don't believe we have an exact match. Start by looking at our 81-090. The wheel diameter is different, but you'd be able to make up for it by adjusting the roller. The other issue if you wanted nylon wheels you'd have to replace them as described in this post here. As this post also describes though, there's a chance this assembly may not be what you need. In that case, the closest match we have is our 23-043. Let me know what you find out.