They are working great. They are so easy and fit the jar perfectly and fit between the silicone fermentation lids and the Masontops Tough Band. They have made fermenting extremely easy for me. I always make sure that I have enough liquid in the jar so that when these cups are in the mouth of the jar and pushed down into place the level of the liquid rises inside the cup about 1/4 of an inch or about 7 millimeters. They are not flimsy. Yes they are thin but they need to be to fit with the fermentation lid and then the final band to screw on. They are thin but strong and well designed. I understand that the makers read these comments and make upgrades and improvements. So I know they added the small holes in the bottom to let water come in, but some small air bubbles still get trapped beneath the flat bottom. I wonder if a mesh design similar to the plastic sprouting lids for mason jars. That would keep all of the veggies down but let the water flow and not allow for any trapped air. I really like these. I used to use different types of vegetables to put on top of my fermented veggies and it was a small pain. This is just so easy now.