The harness is a bit large for our 6 month old Havanese, however the firm structure means she is much happier in yours than in her previous harness.
Have one question re design:the ring at her chest is too low to be usable. The leash keeps getting caught up in her legs. The ring itself is v thick and makes clipping a smaller leash a bit of a challenge. Otherwise great quality!
We followed the sizing chart and they fit perfect. They stay on her face the entire time she's chasing me down on my bike. Protecting her eyes and looking super cool doing it.