Once a month take the magnets out of your tracking collars, turn on your receiver and make sure the collars are working. Leave the collars running for 4-8 hours, while you go to work or overnight. Turn your receiver back on and make sure the collars are STILL working. Then put the magnets back in and check to see the magnets are turning the collars off. NEVER, NEVER UNDER ANY CIRCUMSTANCE - turn your hound loose without making sure your tracking collars are working first.