Men's Barbour Warm Pile Waistcoat / Zip-In Liner is designed to zip into selected Barbour jackets and is an alternative to Barbour's Quilted Waistcoat zip-in liner styles. To double check this liner is suitable for a particular jacket, see the "Recommended Accessories” tab on the jacket's product page for detailed guidance. Barbour recommend ordering the liner in the same size as the jacket.