check the authenticity as follows: 1. first, see if the trademark has the "TOTO" trademark. There are no extra letters. 2. Look at the glaze of the product. TOTO's glazes are all imported, giving off a very white light. 3. Go to the regular dealer designated by TOTO for initial purchase. 4. Look at the toilet. The color should be very close to the color of the toilet ceramics, and the texture is very strong, and it falls slowly when it is put down. 5. Put your hand into the back of the drain. Touch whether the glaze inside the drain is smooth. If it is rough, it is false, and if it is as smooth as the outside, it is true. 6. Each toilet has a number.