The Lindapter 'D2" Recessed Adjustable Tail Clamp has a recessed head that holds the bolt tightly in place which prevent the clamp from rotating during installation. This adjustable clamp incorporates a setscrew tail to accommodate a wide range of flange thicknesses. Lindapter 'D2' Recessed Adjustable Tail Clamps are suitbale for flanges up to 5? and are availbale in multiple sizes.