The DT-1 is a flush mount for the PL2T. Drill a 1.5" hole in the desk top, 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.