A PerfectFit harness came highly recommended when I first acquired my puppy two years ago and I loved the idea of being able to enlarge it as she grew bigger as it comes on three adjustable sections. I did struggle a bit with putting it on correctly at first and adjusting it to fit but I got there in the end! I have to say that she doesn't like having it put on much but this seems to be common with lots of dogs so doesn't:t worry me too much and I comfort myself with the knowledge that I have got her the best harness I could. And once we are out on a walk she clearly couldn't care less and seems perfectly comfortable in it. I have recently upsized two of the sections now that she is bigger. Thank you PerfectFit!