Non-insulated design allows for use in warm climates and can be worn over insulating layers in cold conditions Full coverage minimizes wet, muddy dog cleanup Girth is measured around the widest part of the rib cage. Measurements: X-Small: 17 - 22 in. girth Small: 22 - 27 in. girth Medium: 27 - 32 in. girth Large: 32 - 36 in. girth X-Large: 36 - 42 in. girth Ripstop nylon NEW PHOTOS!