Cat's Best Original 30L (13kg). Cat?s Best Original is a completely organic clumping cat litter made from natural wood fibres. It has superior odour binding properties formed by the natural capillary system of plants making it super effective at trapping unpleasant smells. Additionally, it can absorb up to 7 x its? own volume. Resulting clumps make waste easy to remove allowing the base contents to be left in the litter tray for up to 7 weeks! Compostable, 100% biodegradable and creating significantly less waste, it?s the litter in harmony with nature.