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 around the neck. Generally a properly fitted collar is one that when fastened, will snugly slide over pet's head. Leave 2 to 3 extra inches for collar adjustment, cut off remaining excess and dispose of it in the trash. Wash hands after installing collar on pet. Replace collar every six months, or sooner if needed.