The latest development in the Chromatic harmonica originally invented by Hohner in 1912, featuring revolutionary slide tension adjustment and tone blocks to adjust weight, balance and acoustic impedance. PRODUCT DESCRIPTION HOHNER ACE 48 CHROMATIC HARMONICA, w ADJUSTABLE TONE-BLOCKS AND QUICK-RELEASE SERVICE PLATE, NEW SLIDE DESIGN WITH TENSION ADJUSTMENT SCREW. FEATURES Removable Acoustic Coupling Elements (ACE) modify acoustic impedance to create your own tonal color and adjust weight distribution according to taste New revolutionary VarioSpring – System to easily adjust spring pressure to suit individual playing styles Unparalleled comfort through new ergonomic cover and mouthpiece design CNC precision-milled mouthpiece, closed at the side to ensure silent, airtight slide action Robust nylon zipper case which also functions as mobile workbench Service-friendly and developed to satisfy the highest musical requirements, the HOHNER ACE 48 also offers two revolutionary features: Acoustic Coupling Elements (ACE) enable uniquely variable sound design, while in addition the new VarioSpring – System permits exact adjustment of slide spring pressure to suit personal preferences.