The first is to look, first of all to see the appearance of the cup. Take a look at whether the surface of the inner tank and the outer tank is uniformly polished, and whether there are bumps and scratches;
Second, see whether the mouth welding is smooth and consistent, which is related to whether it feels comfortable when drinking water together;
Third, look at the poor quality of plastic parts. It will not only affect the service life, but also affect the hygiene of drinking water;
Fourth, see if the internal seal is tight. Whether the screw plug and cup body fit properly. Whether it is easy to screw in and out, and whether there is water leakage. Fill a full glass of water and turn it upside down for four or five minutes or give it a few vigorous shakes to check for leaks.
