These tools are used to clean tubes that have sharp bends in them. They consists of a brush or cobalt tip mounted on a piece of flexible shaft so the tool can negotiate the bend.

Cup Brush Tools
Cup Brush Tools Tube I.D.
mm inch
PM-CBT-0500-B 12.7-19.1 1/2 - 3/4"
PM-CBT-0500-SS 12.7-19.1 1/2 - 3/4"