The ornament is square in shape and represents a fine example of the Byzantine interlaced ornament. It consists of interconnected squares, circles and arcs. In the center of the ornament there is a rosette and four more semi-rosettes are placed in between the squares. You can easily remove the rosettes and insert a pattern you like instead.
Byzantine ornament vector is fully editable, just download it bellow, open the file in 2D CAD or vector editing software and customize.