ALUMINUM PHASE PLUGS PAIR, POLISHED and PLATEDIn Stock Does Fit to: 800 Diamond, 802 Diamond, 803 Diamond, 804 Diamond, 805 Diamond. 800D, 801D, 802D, 803D. 803S, 804S. Nautilus 800, Nautilus 801, Nautilus 802, Nautilus 803, Nautilus 804, Nautilus 805. 683, 684, 685, 686, 683 S2. 703, 704, 705. CM10, CM9, CM8, CM7, CM6, CM5, CM10/S2, CM9/S2, CM8/S2. HTM2 Diamond, HTM4 Diamond. HTM1D, HTM2D, HTM3S. Nautilus HTM1, Nautilus HTM2. CM CENTRE 2.HTM61 S2, HTM61, HTM61. High quality aluminum phase plugs, The aluminum phase plug is suitable wherever plastic plugs can be unscrewed. The plastic phase plug is then simply replaced with one of our high quality aluminum plugs. It is not for nothing that B&W uses aluminum phase plugs in the 805 Signature. Through the use of aluminum plugs, the frequency response, which is already very linear for simple plastic plugs, is jointly linearized and heat dissipation is maintained. Sound is further separated from the speakers, and further enhanced naturalness makes it even clearer and more accurate. Phase plugs prevent opposing diaphragms from cutting just as reliably. At the same time, when using aluminum plugs, better heat dissipation in the area of ??the pole core increases the load capacity and counteracts thermal changes in sound. The dynamic midrange driver works with particularly low distortion when a copper layer covers the inner pole of the magnet, while the aluminum phase plug provides dispersion of the higher frequencies. So only the right combination of materials does it. The technical explanation is trite: the combination of the two materials linearizes the inductance of the voice coil. This results in a dramatic reduction in distortion.