XDOG Vest 3.5 “World’s Greatest Dog Harness™️” The XDOG Vest 3.5 Alter Ego is the newest version of the World’s Greatest Dog Harness. It combines weight resistance with resistance bands to provide your dog with all the health benefits of fitness training with every movement.Exercising your dog has never been easier or more convenient as it only takes about 30 seconds a day to put the XDOG Vest on and take it off. As soon as your dog is wearing the XDOG Vest it is immediately exercising.The XDOG Vest is a great enhancement tool for any lifestyle