The outside diameter dimension is 3.5", matching the width of a standard vinyl post, and is also suitable for other types of 4x4 posts. Tube is placed inside the mount, therefore the ends can be cut on site: no precision cutting is required. Set screw is included to lock tubing and to prevent turning. Fasteners are included in the two pack.
Patented design can accept any agnle up to 45 degrees in one of four directions, while keeping the perpendicular directions immovalbel.