The Vic Firth Re·mix Brush Series Features Four Models in the Lineup, Each With Unique Materials for a Versatile Range of Sounds.rm1 - Broomcorn Offers a Delicate, Subtle Brush Sound for Softer Musical Situations. Pairs Well With Rm3 and Rm4 for More Attack.rm2 - African Grass Offers a Great Balance of Softness and Attack. Pair With Rm3 and Rm4 for Added Attack and Volume.rm3 - Birch Dowels Offer Mid-range Volume and Attack While Maintaining an Organic Sound and Feel. Pairs Well With Any Re·mix Brush.rm4 - Rigid Rattan and Birch for the Most Volume and Response. Pair With Any Re·mix Brush for More Attack.