ONE by Josko is a window and sliding door system whose very slim frames have a width of only 5 cm. This filigree construction is a feature of all the products in the series. The interior face of the window may be constructed according to the individual wishes of customers. Thus, they can choose between various sorts of wood, aluminium, glass, concrete and steel. A range of accessories such as a handle, window sill, sun and insect protection and a flat, barrier-free threshold have been developed for this system which also achieves modern insulation values.