Our devices work with ultrasound that interferes with the ability of ticks and fleas to orient themselves. Our products emit a series of ultrasonic pulses that are imperceptible to humans, animals or wildlife, making it perfectly safe to use for babies, kids, adults, and pets. Environmentally friendly contains no chemicals or fragrances and protects against parasites up to 12 months. The frequency range of our devices is imperceptible for humans and animals. How to use: - Fasten the device to the horse’s headstall or saddle, making sure to leave the device’s grid free. Remove the tab to activate the product. 4 green flashes will indicate that the device is powered on. You can verify its continued operation at any time by pressing the button and confirming that the LED flashes in response. At normal temperatures, the device can keep parasites away for 6-12 months after activation. To ensure its effectiveness, the device should remain affixed to the horse at all times. If you also wish to keep the stable free of ticks and fleas, use the Tickless Home device.