So, about the Momcozy S9 Pro breast pump and leaks—our research shows it's kind of a mixed bag. Some people don't have any problems, while others occasionally notice some leakage.

The manufacturer stresses that getting the right flange size is super important to prevent leaks and make pumping more comfortable and efficient. The pump comes with a 24mm flange, but you get inserts of different sizes and a nipple sizer to help you find the perfect fit. This is supposed to help cut down on leaks and improve the pumping experience overall.

From what we've found, lots of folks say that putting the pump together properly and making sure everything is aligned right can really help with leak prevention. Trying out different flange sizes and always checking for a good seal also seems to be key.

So, yeah, while there are some reports of leaking, using the right size flange and making sure everything's put together correctly can make a big difference.

If you keep having issues, it might be worth reaching out to Momcozy's customer service or trying a different flange size to see if that helps.

The comfort of the Momcozy S9 Pro breast pump is pretty well-regarded. Our research shows that most folks find it comfortable to wear. Because it's hands-free and wearable, you can go about your daily routine without feeling confined or uncomfortable.

It's designed to be lightweight and ergonomic, so it doesn’t settle like a heavy burden on you while you're using it. Plus, the soft silicone flanges adapt nicely to your breast shape, which adds to the comfort and efficiency.

That being said, comfort is personal and can vary. Some people have mentioned that it might take a few tries to get the suction level and fit just right. The manufacturer offers adjustable suction levels, so you can tweak it to find what feels best for you.

The flanges come in two sizes, 24mm and 28mm, which fit most people, but if you need a different size, you might have to buy it separately.

Another thing that helps with comfort is that the Momcozy S9 Pro operates pretty quietly. It’s discreet enough that you won’t be drawing attention to yourself with loud noises. It also has an LED display that makes it easy to keep track of your settings, though you’ll still need an external timer for the pumping duration.

So, overall, the Momcozy S9 Pro seems to do a good job in the comfort department. Just be ready to play around with the settings a bit and maybe look for a different flange size if the included ones don't quite do the trick.

According to the manufacturer's description, the Momcozy S9 Pro breast pump can hold up to 180ml of milk, which is about 6 ounces.

But from our research, it seems some folks have found it can hold closer to 8 ounces if filled all the way. That said, filling it to the brim isn't the best idea because it might lead to leaks, especially if you're moving around a lot, bending over, or lying down.

The silicone material and seals do a good job of preventing leaks during typical use, but they're not foolproof if the pump gets tilted too much. To avoid any mishaps and make your pumping session more comfortable, sticking to around 120ml (4 ounces) is a safer bet.