Our now 3 year old cockapoo has had the same PerfectFit harness since they were around 1 year old. When our friend bought a new PF harness, it prompted us to measure our cockapoo. I called PF and received exceptional service from the advice and patience whilst I chose a new harness colour. Nothing seemed too much trouble and we also received exceptional service when we bought our first PF harness. Our cockapoo was just inbetweeen 2 sizes and it sounded like the exchange process would have been stress free had we needed to use it, but luckily we didn’t and it was a perfect fit for our cockapoo 😊 Can’t recommend PF enough for the customer service and product quality.