This promotional offer applies only to the listed variants starting with 502842xx xx variant identifier greenwoods natural clumping cat litter 8l this biodegradable all natural clumping cat litter is made from pure natural plant fibres from 100 renewable sources it is compostable environmentally friendly and has an amazing 700 moisture absorption thats up to 7 times its own weight in liquid and three times as efficient as traditional cat litter this litter has a fresh woody