Does what it says on the tin - this harness really is a Perfect Fit, especially as my frenchie has spinal issues which means she's even more "chesty" than the average frenchie. The harness is so easy to put on, easy to adjust & I love that you can just switch out the top piece if you want a different colour. Customer service is second to none. I wasn’t sure of sizing so sent an email over & got a really quick reply with helpful advice. I tried 2 different top pieces & you can just return whichever pieces you don't need. And it turns out the sizing advice on the website was spot on too!