The harness I got and the one my breeder recommended was the Ruffwear Web Master. It has a 3 point strap that prevents escape for dogs like iggys with skinny bodies and small heads. I have linked the one i have below. I have it in XS and it fit my iggy from mid puppy to fully grown. You def want the 3 point to prevent escape. https://www.amazon.com/Ruffwear-Multi-Use-Support-Everyday-Twilight/dp/B01N10H776/ref=sr_1_2?crid=1ISR4U2LR84SR&keywords=ruffwear+webmaster&qid=1680781308&sprefix=ruffwear+webmast%2Caps%2C695&sr=8-2