How to tell whether a tempodrop weather bottle is authentic or fake?

The genuine Tempo Drop is a Perrocaliente series product of Japan's 100PER company. Just certify this brand. The rest are all copycats. The small weather bottle I bought at an authorized agent store in Hong Kong the year before last cost 450 Hong Kong dollars. It is original from Japan. Imported, the cheapest genuine product I checked on the Japanese website is 5,570 yen, which is several times more expensive than the fake ones