Manufactured to the highest standards, the top quality construction and accurate intonation make these bells the best vaule available. The ChromaNotes colors make it more fun to learn and play along with Boomwhackers! Each metal bell is marked with the proper note and number to help children learn the musical scale. The desk bell are struck on top for ease of use at any age or ability. This set gives you the extended range of a Low A to High E. Add this to the CNDB-D and CNDB-C (sold separately) to create a 20 deskbell set!