If we talk about metal -plastic pipes for the water supply, then they consist of several layers. The inner layer is made of aluminum foil, which on both sides is glued to a thick layer of plastic. This design feature combines the best sides of plastic and metal pipes. Such products are easily bending, so you can bypass all obstacles and do not use additional fittings. They withstand high temperatures and are great for heating and water supply. There is one feature of the installation of such a pipe: a piece of the product of the size you need is crimped on both sides and is connected using fittings. This type of connection is reliable and eliminates all kinds of leaks. But in this case, a special testing tool will be required. The price of fitting is very high. There is also one more feature: the water supply in this case is completely collapsible and it is very easy to mount. If you are interested in such products, then the company Plasttorgmonta offers metal -plastic pipes that remarkably tolerate pressure drops. But they have one drawback — this is their price.