Gooby Soft Mesh Harness for Small Dogs Model Notes: Wearing Large, Weighs 20 lbs Neck 13"(inches) Chest 18.75" Estimate Sizing By Weight S: 5-10 lbs M: 11-16 lbs L: 17-23 lbs SEE PRODUCT DESCRIPTION FOR EXACT SIZING Over the Head Entry Adjustable Nylon Strap 100% Polyester Mesh and Please check the sizing chart and following the chest size before purchasing.