Innovative Percussion Concert Bass Drum Mallets Differences The CB-1, CB-2 and CB-3 feature solid wood cores and thick synthetic felt liners and covers for a full dark tone quality, while the CB-4"s unique flexible synthetic ball head results in excellent articulation and punch, with no contact noise. The CB-5 "cartwheel style" rollers feature a smaller red oak handles for greater balance and control and are specifically designed for rolled passages.