Heil Sound DT-1 Flush Mount for PL2T, SB-2 and HB-1Heil Sound DT 1 Flush Mount for PL2T, SB 2 and HB 1 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. For the PL2T, SB 2 and HB 1