Maximum sound. The Vic Firth American Custom Keyboard Hard Phenolic 1" ball mallets are best used on bells and xylophone. The mallet head consists of phenolic plastic for maximum crystal-clear attack. With a birch shaft you can expect rigidity and a solid consistent feel. Perfect if you want the extra reach without the flexibility of rattan. With a 16 length these Vic Firth American Custom Keyboard mallets were designed for use on bells and xylophone.