To check that the harness is not too tight, ensure you can pass two fingers between the harness and your dog. Leash should be attached to the D ring for a safe and secure connection.To properly fit a harness for your dog, it is essential to accurately measure the chest and neck. Follow these guidelines & refer to diagram for precise measurements: • A Chest: Begin at the bottom of the rib cage, wrap the tape around the torso, go over the back, and then back down to the starting point. • B Neck: Measure around the thickest part of the neck, just above the shoulders, to ensure a proper fitTo ensure that putting the harness on your dog is as simple as possible, Unclip all fastenings and we advise loosening all of the straps before using it for the first time. You can adjust the straps to ensure the ideal fit once the harness is on.Place the harness over your dog's head.Establish contact with the chest by raising the chest plate. Securely fasten the clips. Adjust to fit ensuring that you can fit two fingers between the harness and body.