Why Zip Up Microfiber Fleece? Everyone has that one sweater they always wear when the weather gets chilly. Apparel within our fleece collection is designed to be just that but for your dog. The Zip Up Microfiber Fleece Vest and its sister product the Zip Up Fleece Vest are in many ways alike, but not without some key differences. How it differs? - Double Layered Microfiber - Extremely soft to touch. - Great next to the skin. - Multiple Sizing Options - seven sizes from X-Small to 3X-Large. Fits medium sized dogs up to 50 lbs. - Stretch fit: gives flexibility and ensures a perfect fit.