The lid works great, no leaks

I could not tell you if it was leak proof or how it works as it does not fit any mason jar that I own wide mouth or small mouth.

The lids are great...leak proof and easy to clean

Great top, no leaks

I have had no leaking even when the bottle gets knocked over and the straw is still up

No leaks yet and cutting the straws to size was easy

Good fit and no leaks

These work great, no leaks, fit perfectly on my 64oz hydroflask

Bad fit, sweats n leaks.

That and there is a slight leak if it leans or falls over, but that is the same for all straw lids like this.

Easy to install, no leaks and let me make a nice color mix on my Hydroflask

It was a vibrant color and leak proof

The lid works great, no leaks

Great top, no leaks

They are a great fit, no leaking from the seal and the paracord handle has held up almost perfectly over the last 9 months

I could not tell you if it was leak proof or how it works as it does not fit any mason jar that I own wide mouth or small mouth.