The DT-1 is a flush mount for the PL-2T, SB-2 or HB-1 booms. This mount ensures a smooth fit and noiseless boom movement. Drill a 1.5″ hole in the desktop, then tighten the large washer and nut of the DT-1 from below the desk. This creates the ultimate in a classy mount for all Heil booms. The brass insert accepts a 1/2″ Stem. Requires a 1.5″ hole for mounting and will mount to surfaces 1/2″ – 2″ thick.