I've tried o.b. in a different size before and had no issues, but with this one I found there should be an applicator with it. It's ultra so yeah it's gonna be bigger. A bit difficult to insert, but everything else is good with this product, it does what it's supposed to.
I really hated this product. They are a good price, but that is the only good thing about them. They have no applicator so they are very messy to apply. I find I could never get it applied just right.
Decided to give these another try after not using them for so many years. Now I remember why I disliked them so much. Messy, uncomfortable and highly impractical. They are not easy to get in and once you get it in the string is too long. I wouldn't want to attempt inserting these anywhere but home. As far as leak protection goes I'm not sure, I'll update with that info shortly...
UPDATE: So the leak protection is really good! Everything else about this product doesn't appeal to me. It's unpleasant to insert however once it's in it does its job. For that alone i'd bump it up a star and a half to a 2.5 star rating.
These reviews are the subjective opinions of ChickAdvisor members and not of ChickAdvisor Inc.