This brush is a Fiberglass model only. The fiberglass tip is about 1/4 the size of the tips you will find in the Refillable Pen Brush (BT-1000). It is an excellent detail brush, and gets those hard to get places with even more control than the BT-1000. Again, best used with a damp paper towel under the coin to catch the fiberglass shards that will fray from the cleaning brush.