The creation of a cylindrical entrance door can be realized with Ronda, combining a pair of Rondina with equal diameter. This solution allows a suitable passage for people, carts, hand luggage and possible bulky goods, eliminating architectural barriers. The circular and transparent shape, its perfect operation and its silentness, make it a door of architectural design, creating a stylish entrance. PONZI cylindrical doors can be perfectly integrated into every type of architectural structure: headquarter offices, showrooms, hotels and airports.