With OdorZap Crystals. Helps to clean teeth and freshen breath. 2 Large chews. The special formula in the Hartz Dental Nutri-Fresh chew utilize the OdorZap system. Hartz' unique OdorZap system has crystals containing chlorophyll. The combination of the chew's distinctive abrasive texture and OdorZap crystals help to neutralize odors and freshen breath as your dog chew. Hartz Dental Nutri-Fresh can be used daily in addition to regular veterinary visits as a great way to maintain your dog's dental health. This product is intended for intermittent or supplemental feeding only. Made in USA.