The Trombone Lyre clamps on any trombone bell rim. At this location the music is at the ideal distance from the eyes for easy reading. The attaching clamps are covered with slip resistant non-scratching material which will not mar the finish of the instrument when properly tightened down. Lightweight and durable as molded from black ABS. Spring loaded Wind Clip holds windows for easy flipping. Can also be used on marching brass instruments. Supplied with five clear plastic windows and two plastic rings.