Ultra Cat Health Monthly Monitor Crystal (B00AYT9ZXK)

An early illness detection program that is easy to use and works with all types of litter. Simply pour on top of a newly filled litter box. After your cat uses the litter box, wait at least 10 minutes. Compare the color of the monthly monitor crystals to the color scale. If the crystals are an abnormal color, it is recommended you contact your veterinarian.