lets talk nipple shields?

so I am just finding out about these. I never knew they existed when I was nursing my son 10 years ago. we had latch issues big time and because of that I only breastfed a couple of weeks.

so my question is what brand did you buy that worked well with you and your baby? and I also see from my Google search there are different sizes. How do you know Which size to buy? baby girl will be here in July and I think I'm going to pick some up for just in case because I want to be successful with EBF this time around.