At installation and fastening of the children's holding devices it is necessary to switch the inertial coil to the mode of automatic blocking. It will prevent dangerous movement of the children's holding device at the road accident. To include the mode of automatic blocking, completely extend a seat belt from the inertial coil. Then fix by a seat belt the children's holding device, following instructions of the manufacturer of a concrete product. The seat belt will attract the children's holding device and will remain in the blocked state.