I'm not sure of Josie's weight but she was at 77lbs 2 months ago. I'll bet she is with in 5lbs of that. She will be 1 year old on the 11th of next month. That is the 2 inch collar. We really like it. Josie was so proud when we put it on her it was hilarious! We took it off at bed time because it's very stiff. She look at us like HEY! But she fell right a sleep. I figure we'll break in like a pair of shoes. Man that baby is well made. The pictures of Blocky Dog collars don't do them justice. Now we are trying to figure out which next black or pink.