Dremel 537-02 brass end brush
537-02 uses a narrow 1/8-inch brass brush head.

How to choose
Consider this shape for an area where a broad brush wheel would brush against adjacent surfaces. Check the listed material and the size of the recess first.
Compatibility and limits
1/8-inch brass end brushes · two mounted heads
Care
Use the brush tips with light pressure and check the speed limit printed for the exact brush. Dremel’s cleaning guide explains how pressure affects the working bristles.
Questions before buying
Which brass brush gives the most localized contact in this group?
The 537-02 uses the narrow end shape. Compare the half-inch 536-02 cup if you need a larger contact patch and the opening has the space.