Make your cat more comfortable If this is the first time for you kitty, try to ensure that you make this experience as positive as possible. We suggest you adjust the harness to fit your cat snuggly but not too tight, with the two fingers test. Notice: Always look at the size chart for chest girth and length and confirm the size before you commit to buy. The harness and leash set is not for pet's chewing, please do not leave the leash and harness set on your pet unattended.