CatS Best Original Uses The Power Of Technologically Refined Active Wood Fibres As A Clumping Litter. These Are Manufactured Using The New Ics Wood Fibre Technology** Process. Liquids And Odours Are Absorbed Particularly Effectively And Encapsulated Deep Inside Up To 7 Times Their Own Weight. Therefore CatS Best Original Can Remain In The Litter Box For Up To 5 Weeks Before A Complete Change Is Necessary.