IsoAcoustics Professional Monitor Isolation Feet - Iso-Puck (Pack Of 2) The ISO-PUCK upper flangesuction cupdesign adheres to the underside of the cabinet making the upper isolator live with the speaker, while the lower isolator anchors to the supporting surfaceAll the energy is managed within the core of the ISO-PUCK isolators which are carefully tuned to provide superior isolation and control while remaining on-axis. The low-profile design makes the ISO-PUCK series the ideal solution on meter bridges, floor stands, consoles, desktops, millwork, or soffit mounted. These isolators decouple studio monitors and speakers from the supporting surface to eliminate the transfer of energy and the resulting sound smearing and coloration. Even placement on the most solid surfaces will greatly benefit as the internal reflections coming back up from the supporting surface are attenuated to eliminate the smear and provide greater sound clarity and open up the stereo image. What is the differenc