ESS Speaker AMT HEIL Ribbon Replacement Diaphragm AMT, 689-1108 ESS AMT Speaker HEIL Ribbon Diaphragm Part # 689-1108 Original factory ESS Part Hand folded, USA made Size: 1-11/16" x 4-11/16" (43mm x 119mm) Impedance: 4 ohm, DCR: 3.7 ohm