Instruction: Answer the given question by extracting information from the supporting document.

Input:
Question: How is the hole in the outer glass layer sealed and has the seal held? Any condensation?
Document: I bought these glasses about 6 months ago, and I've been using them, a few times a week, for about 4 months. I'm now down to the use of 2 glasses, as I just noticed this morning that the 2nd glass of the set has a broken seal. So, there is condensation between the glass walls.The glasses are lovely and the dimples for holding the glass are very convenient. However, because of durability, I would not recommend them.
Ordered two cases. Out of 16 glasses, 2 of them have a leak in the glass base. I think when these 2 glasses were separated from the blowpipe, there may have been a tiny air bubble, so when you wash the glasses, water seeps into this tiny pinhole (hole not visible, just the slightly raised &#34;pinched&#34; section on the base of each glass), & the condensation droplets can't be removed.
CHANGE OF OPINION . . .I am the author of the below review (original one and had rated them 5 star) Now that I have run these through the dishwasher - my opinion has changed radically. The double walls had water in them the first time through the dishwasher. It does not empty out completely and appears as though there is a defect in the seal on the bottom, between the walls. The water must be forced into a small hole by the dishwasher.
I just bought a second set of these glasses. As mentioned by other reviewers, these are hermetically sealed and do not have the plastic silicon seal that the Bodum glasses have. They also feel slightly heavier (just barely noticeable, but not heavy in any sense of the word). I've found that the dimples on the side of the glasses actually make them easier to grip - I feel less worried that they would slip. Highly recommended, and the customer service from Ozeri is great.
I bought these cups as a gift. I used them before and they work really well at keeping your drinks cold and condensation out. The best part of the glasses are that they are completely sealed, so no water or residue gets inside. They are more fragile than your average tumbler glasses, but for the price it can't be beat. I like them better than the brand found in most stores since they don't have a plastic plug on the bottom that can fall out.
I've used traditional (white porcelain) cappuccino cups for many years and wasn't sure what to make of these, but here's what makes them great:- Double Wall really works. There's no heat around the outer layer of glass, which is better than traditional porcelain where you have to hold by the tiny handle due to heat transfer along the sides...- Clear glass is really nice for cappuccinos and lattes because you can see exactly how much espresso/milk/froth you're pouring, and it just looks great.
These truly are very attractive glasses, especially when you have the liquid in them & can see the double walls. The glass is incredibly smooth and silky feeling, and the dimple for holding them is a great feature. They hold 8 oz of liquid (filled to the rim, so realistically somewhat less than 8 oz. ), so are only big enough for some things I drink such as wine & a small juice - I wish they held more volume.
It look interesting but I've attempted to placed hot liquids in other glass cups that 'were made for hot liquids' and ended up burning my hands. I wasn't convinced that the space between the inner and outer glass would provide enough of a barrier to keep my hand safe. Surprising, it was 100% accurate. I was able to pour hot water from my Keurig into the glass and it pick it up with no ill effects.
These are the best double-walled glasses we've tried. They are light, good looking, and comfortable in the hand. Little or no condensation on the outside of the glass, even with lots of ice in the glass. I'd give them as gifts.
I was really in love with these, but even after hand washing only, one rim has cracked and the hole in the bottom of the other has opened so it fills with water.Beautiful product, once they address these issues.
Answer: One cup had condensation out of 4 ordered and a replacement was send.