Promark Diversity Series System Blue - M Vibe Mallets. As the name implies, this series has been designed by The Blue Devils percussion staff to be a diverse line of mallets for indoor and outdoor percussion. The eight mallets in this line cater to a variety of players and educators by featuring four graduated vibraphone mallets and four graduated marimba mallets designed for use with natural or synthetic bars. These mallets hold up to any musical demand while still achieving a true, fundamental tone from the keyboard, and are perfect for ensembles seeking clarity and articulation.