Violin Bow Comb:Make violin bows work better with rosin and make rubbing rosin easier and more efficient Rosin Spreader:Easy to use, after the rosin is used up, use a bow comb to gently and slowly comb the bow from the bow handle position to the end of the bow, repeat 2-3 times and you're done! Viola Bow Comb:Compact and portable for enhanced sound quality Cello Bow Comb:The rosin will be more evenly distributed on the bow hairs after use. Bow Comb:More even distribution of rosin on the fiddle bow