Easy to mount dispenser will operate every 15 minutes, 24 hours a day for a full 30 days. Use bug killer refills which contain pyrethrins and will kill flies, monsquitoes, gnats and small flying moths or use Country Vet scented spray refills for 30 days of fragrance. Battery operated dispenser for use with all Country Vet 6.4 ounce metered products. Batteries not included.