Magnetic Centering Head with Vial, 6 in and Larger Pipe Capacity, Medium ORS NASCO Hold open clip for continuous spraying Self adjusting Hold open clip for continuous spraying Self adjusting "duck" packing for lifetime leak proof seal Metal construction built for frequent use Threaded front for adding attachments Allows quick and easy disc attachment and removal for multi step processing One piece Y shaped body design with magnetic legs Built in dial with 2 1 2° increments that turns 360° Hardened center punch marks set position by taping with a hammer Used to establish and mark a centerline at any angle around circumference on a pipe or tank or as a protractor level Excessive heat can damage magnets