Pairing a collar to an Astro 430 From the Main Menu, use the arrow keys, highlight and then press ENTER on Dog List. Using the arrow keys, highlight and press ENTER on Add Dog. Follow the on-screen instructions. With the collar off, press and hold the Power button on the collar until it emits two beeps (about 2 seconds), and then release. The status LED will flash green indicating the collar is ready to be paired. If desired, use the arrow keys and ENTER to input a name for the dog. Highlight and then press ENTER on Done when complete.