OKNOPLAST windows are recognized by architects and are applied in many house designs. As big glazed surfaces are an intriguing solution, the company strives to keep up with the trends and fulfil the expectations of customers by offering several types of patio doors, among others the HST lifting-sliding doors. Their unique design makes it possible to create very large glazed surfaces with the maximum surface area reaching 14 m2. The opening leaves width amounts up to 3 m. Although they are large-sized and of significant weight, they open easily. Our offer is complemented by the PSK and PSK-Z tilt-sliding door system and the PSK Atrium hoisted-sliding door system, patio windows, and balcony windows.