This promotional offer applies only to the listed variants starting with 619587xx xx variant identifier biokats micro white fresh is a natural clay clumping litter with fine white grains which are very popular amongst cat owners because of their high absorbency cats also prefer fine grains because they are kinder on the paws biokats micro white fresh is made from especially fine white grains and is up to 100 dust free this fine grained litter has a great fresh springtime smell it