There are Kang Biting in China and Opmon, Giant, Wade, Universal, BSN and Bora abroad. When I have eaten Opal and Giant, I feel similar, and some friends have eaten Kangbitou, but Ewan is not so good. In fact, this thing varies from person to person, and what suits me may not be suitable for you. If you buy it online, the price is cheaper and the price is different. 2 kg of opal is between 160~ 180. I can eat it for a month if I save some food.