ProMark Jim Wunderlich JW5 "System Blue" Hard Marimba Mallets feature a round synthetic core with brass inserts and a layer of latex for maximum articulation. Finished birch handles have an ultra-smooth texture similar to rattan and an extended durability that makes them suitable for both indoor and outdoor use. Designed to meet Jim Wunderlich's exacting standards, they provide the lush tone demanded for concert settings.