FP PET SITTER CAR HARNESS LG Four Paws Pet Safety Sitter, Large Car Safety Harness & Walking Harness All In One Dog owners can now rest assured knowing their dog is safe and secure when traveling in cars with the Four Paws Pet Safety Sitter. It prevents dogs from jumping out or disturbing drivers and passengers. Features a handy buckle that attches to dog's leash. Available in five sizes.