there are two types of dunnies in Japan. this is the 'anglo 3000' (this was the one in our hotel room, but they were the same in the pblic toilets as well) when you left the lid, the second layer has a pressure sensor so when you sit down is does a 'pre flush'...wierd. then you have a panel of flush options plus the standard flush button. If you don't get it right you could be in for quite a surprise!