Biokats classic 3in1 cat litter is a high quality clumping litter made of three different sizes of granules this unique combination supports a quicker odour binding improves the firmness of the clumps and allows for extra economical use this litter combines large medium and small granules the large granules have particularly large pores which absorb liquids and unpleasant odours like a sponge the medium granules help to form extra firm clumps as they are the perfect size the fill the gap