The AdirPro 1-Inch Fixed Target Corner Prism has an offset which is always constant in corners or against a wall. This AdirPro prism can be moved up to 180 degrees and features an easily visible circular level. In addition, the monitoring prism is designed with a quick release button making it easy to slide on any pole. With a compact and sturdy body, this 1-inch corner or wall prism is ideal for every construction and surveying job.