The first thing the toilet is a sanitary device, consisting in full complete set from bowls (it also named of the device), the reservoir and mechanism for lowering/water stopper. The most modern types of toilets stuffed with special electronics, which produces drain automatically, once You move away from him.
At first glance, it seems that the device is quite simple and nothing complicated in it, but this is a misconception, because even from the shape of the bowl depends, how effectively water was wash it from the inside. This is not to mention the material and its brand, characteristics of which depended the durability of a bowl. Plus, the type of connection, type of drain, etc., etc.
From the GOSTs (state standards) for toilets impose some requirements: installation height should be 0.4 m; the device must withstand a load of 200 kg; the drain tank should have a capacity at least 6 liters. The documentation must include characteristics of the efficiency of the rinsing of the bowl.