This CRL Header Mounted Free-Swinging Top Pivot is secured in masonry, or to metal, to allow for a free-swinging pivot. For use with Patch Fittings such as Cat. Nos. PH20A, PH21A, and EUR420, or any Top Pivot with a 19/32" (15 mm) diameter hole. Secure in masonry with the included brass masonry anchor, or secure to metal in a tapped 8 mm threaded hole.