HW Brass-Saver for trombone is the easiest and safest* way to clean saliva and corrosive mineral deposits from the inside of your horn. The patented design features a non-metal flexible lead pipe/slide brush (approximately 1" diameter and 77" long) that won't scratch or get stuck. The special fiber will not shed, shrink, or swell, can be used wet or dry, and stands up to the chemicals in cleaning solutions.