Contour Messenger Pet Carrier Bag. The Contour Messenger is an amazing innovation in comfort and design. The ultra thick padding, contoured spine, and shock absorbent shoulder strap create the ultimate comfort for you and your pet. It features an expandable mesh "tower" that gives even more room inside for your pet as well as increased visability. It has a large zip opening to put your pet inside and a smaller zip opening in case your pet like to stick his head out! And this carrier is fit with a convenient pooper scooper bag holder.