12 in a pack, brass bush bearings for all sorts of models not just railways, 1.5mm bore in body 2.5mm diameter, 5mm diameter flange 1mm thick, the whole thing is 6mm long with a closed end. See picture for shape.

These are an end-of-line offer but I can make variations on the product if required, though pricing will vary according design and numbers off.
Condition is New and I have many of them if you want to do a deal on multiples.