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Voyager Step-in Lock Pet Harness – All Weather Mesh, Adjustable Step in Harness for Cats and Dogs by Best Pet Supplies https://www.amazon.com/dp/B0844Q4KTY/ref=cm_sw_r_cp_api_fab_PowDFbWW7SA5P

Size small fits necks 9.5in-12in and chests 13-20in for dogs up to 20 pounds.