Place collar around pet's neck, adjust for fit, and buckle in place. The collar must be worn loosely to allow for growth of the pet and to permit the collar to move about the neck. Generally, a properly fitted collar is one that when fastened, will snugly slide over pet's head. Leave 2 or 3 inches for extra adjustment. Cust off and dispose of excess length. Wash hands after installing collar on pet. Replace collar every 6 months or sooner if needed.