The Balance Harness is sized based on girth measurement instead of weight or breed. This allows for a more custom sizing recommendation. Please measure your dog 2 inches behind their armpit/elbow and compare that measurement to our sizing chart. This will give you the best fit for your individual dog.
This video on troubleshooting and fitting tips should be helpful as you learn to fit and use the balance harness:
Please let me know if you have any other questions.