High quality lights. They fit my deck posts 3.5 x 3.5 with the adapter which is metal not cheap plastic. Screws on 2 sides. Love the look. Bright white light which is exactly what I wanted. Worked the evening following installation and stayed on during a wicked wind storm. At 3am they are still lighting the deck. Came packaged well. No issues at all. I highly recommend them and the company.