To compliment our PBL-20 Clave Block, we have added a higher and lower pitched version to offer you three tones. Pitched in thirds these blocks use CDV (Chamber Density Variation) Technology. This exclusive Pearl process allows all three blocks in the series to be the same dimensions, but still differ in pitch. Differentiated by to exciting colors Neon Green (High), and Neon Orange (Low), the family of Pearl?s Clave Blocks will certainly find a home in all musical applications.