The set of Neco ADJUSTABLE trolleys for upper hanging rail and lower concealed rail for sliding doors. It consists of all the elements necessary for the installation of 1 interior door and 1 exterior door in cabinets with panels of a maximum of 23 mm thick and with a capacity maximum load of 50 kg of weight per panel. This set is provided with a soft closure system for better movement and smooth braking. The components of this are made of steel which gives it greater resistance. The Neco trolley set packaging has a single package with all the elements ready to install.