Reversible windows Cardiff. Effortless function and design for our Cardiff customers. The Veka Reversible window. Sometimes you want to open a window without worrying about curtains, blinds, high-standing taps – or ornaments that happen to be sitting on the sill. That’s one advantage of the Veka Reversible window type, which swings outward through 180°, effortlessly. Anti-slam hinges and a built-in restrictor mean the window stays open and secure at just the angle you want.