PETKIT Air Purifying Refills for PuraX PuraMax Self-Cleaning Cat Litter Box, 100% Natural Ingredients Odor Remover, 4 Bottles Odor Eliminating Replacement Refills, Quickly Odor ControlReplaced air purifying refill (4 bottles) is only suitable for the PETKIT PuraX and PuraMax automatic cat litter box, and K3 air purifier smart spray. It is not suitable for the Purobot Ultra and Purobot Max Pro self cleaning cat litter box. 50ml bottle*4 bottles Effective Deodorization: Quickly removes odours, targeting smelly molecules and breaking them down, always keeping air fresh in your room. 100% Safe: The main ingredient is plant extract, no