First of all, this critical review is not directed at Eight Ounce Coffee. Made several purchases with them and they are a fantastic seller! Problem is with Hario and, honestly, myself for not noting this item isn't made in Japan like many other Hario products I've purchased. This double wall glass is made in China and the quality is not good. Major defect occurred on first use. Point where bottom of glass was separated from glass pipe during manufacture was not sealed properly. Resulting weak point separated when hot liquid was poured in glass leaving a hole in bottom of glass. Popped like a blister leaving small glass chip on counter. Once defect occurred I checked reviews on internet and saw several instances of same problem. Don't believe these glasses are intended to be vacuum insulated but assume letting air pass makes insulation less effective, which is main selling point of double wall glass. Worse yet hole will allow water to enter air space between walls during washing, resulting in water or water stains on inner surface. As mentioned I don't hold Eight Ounce accountable, their web page states glass is made in China. They also have a reasonable return policy but don't cover return shipping so it doesn't make sense to send defective glass back from my location in eastern US. I own a considerable amount of Hario glass but recommend passing on this product or 15 oz version. For the high price it's not worth it. Live and learn.
