DO NOT BUY ROZ 858 toilet bowl. I have just purchased it and it is totally horrible and a waste of my money. The toilet bowl have serious leakage problems. The first time I installed in my house and it leaked. The retailer exchanged it for me and when I checked the toilet bowl before the exchange, I realise the underneath of the toilet bowl was patched and the patch just came off so easily when I touch it once. I was very unhappy and I had to go down to the main office to get a good toilet bowl set instead of a "fixed" version. At the retailer's main building/warehouse, I saw all ROZ 858 model boxes laying in the unloading bay with the toilet bowls inverted in their boxes. Workers are all patching the ROZ 858 models with some waterproof plasticine. It was obvious what was happening; they were patching to make sure water does not leak from the toilet bowls. This proves a point: Most ROZ 858 models has serious water leakage problems. At the end, we could only exchange for a model and hope that it will not leak. If you do not want to have problems repairing toilet bowls, i suggest you get other better models. Roz 858 is definitely one model you must avoid buying. DO NOT BUY EVEN IT IS ON SALE. The flushing system is horrible. The flush is so weak, even with a full flush, it even can't flush toilet paper down. HORRIBLE. I had to flush mulitple times to get the toilet paper flushed away. So remember DO NOT BUY ROZ 858. For other models from ROZ, I'm not sure but I hope other people can share their comments as well.