This door is so popular at our house, it's almost a tourist attraction. We wanted a new shower door to give maximum room for getting in and out of the shower. We wanted the room to look open and light. We didn't want to see big metal frames and hinges. This amazing door does it all. The design is really clever, and construction is rugged. Hinge pins, at top and bottom, enable the door to pivot on the edge of a narrow glass side panel. When closed, the hinged edge of the door rests behind the side panel. Measure the opening carefully and make sure you order your door in the correct size. Each size has a few inches of "play" so you can adjust width precisely to the opening. Before finding this Kohler door at Wayfair, I priced doors with similar qualities (maximum opening, "invisible" hardware, great appearance) at the local glass place and online. Good ones were hard to find, and they cost thousands of dollars.