Designed by the Respected Marimba Soloist, Teacher and Masterclass Instructor, the Vic Firth Robert Van Sice Signature Marimba Mallets Were Designed by Their Namesake and Feature an Exclusive Hand-wrapping Technique That Virtually Eliminates the Sound of Bar Contact. A Special Interlocking Stitch Pattern Maintains the Integrity of the Head. Models With a Rubber Core Are Mono-tonal, While the Synthetic Core Models Are Multi-tonal -- Allowing the Sound to Brighten and Darken as the Dynamics Increase and Decrease. The 17" Maple Handles Provide Excellent Feel and Control at Extended Intervals.