Hohner's tremolo harmonicas are double reed instruments. The bottom row of holes features the same notes as the top row, tuned slightly higher. This special tuning creates the tremolo's distinct sound, a beautiful vibrato effect with a richer tone. These harmonicas are primarily used in ballads, folk, reggae & gospel music. This 24 hole model produces a beautiful vibrato effect as you play a traditional ballad, folk song or gospel favorite. Three complete octaves allow you to play melodies using the lower notes missing from most diatonically tuned harmonicas. The Echo Celeste features 48 silver brass reeds, a padded, zippered case, and laser engraved covers.