This item is essentially a modern day snake. There are no metal parts, so there is no risk of sratching the interior of the horn. The brush is a good sized high-loft affair attached to an 86-inch long flexible "snake" similar in build to a zip tie. Thereis a plastic ball at the opposite end used to help thread the snake through the horn's tubing. Can be used on the main handslide as well as all tuning slides, and is safe for passing thru your rotary, Thayer and other valves. -cdp