Kamui 1.21 chalk contains a much finer particle size then the standard chalk. The purpose of this is to maximize the friction and offer a larger sweet spot to generate more spin to the cue ball and no miscues! Manning recommends this chalk for players that want to chalk every shot. If your a player that doesn't chalk every shot or forgets to chalk Manning recommends the Kamui 0.98. It applies to your tip like butter and can last a whole game without having to chalk.