The American Recorder Technologies SOUND BANK Model 4 MULTI-D acoustic monitor panel for trombone, flute and most woodwinds gives players an innovative tool to improve their sound. With this panel, you can hear yourself better during performance and capture more of your instrument's true tone through the PA system. Made from scratch-resistant acrylic, the MULTI-D reflects your sound back to you, increasing volume without feedback. Its compact, angled design allows the trombone bell to rest near the panel while the slide passes by unimpeded. Precision-crafted in the USA, the MULTI-D delivers years of reliable performance for hardworking musicians seeking to refine their craft.