External neodymium ring magnet, textile dome, ferro fluid, copper clad alu VC wire, 4 ohms

External neodymium ring magnet, textile dome, no ferro fluid, rear chamber, 800 Hz res. freq., copper clad alu VC wire, 4 ohms

Ferrite magnet, textile dome, internal chambers, copper clad alu VC wire, 750 Hz res. freq., low distortion, very even off-axis freq. response, 4 ohm,

Ferrite magnet, textile dome, ferro fluid, internal chambers, copper clad alu VC wire, 750 Hz res. freq., low distortion, very even off-axis freq. response, 4 ohm,

Dual neodymium magnets, silk dome, no ferro fluid, heat sink, copper clad alu VC wire, 1.0kHz res. freq., 4 ohms, 94dB/2.83V

Dual neodymium magnets, silk dome, ferro fluid, heat sink, copper clad alu VC wire, 1.0kHz res. freq., 4 ohms, 94dB/2.83V

Dual neodymium magnets, silk dome, no face plate, heat sink, copper clad alu VC wire, 1.0kHz res. freq., 4 ohms, 94dB/2.83V

Dual neodymium magnets, silk dome, no face plate, ferro fluid, heat sink, copper clad alu VC wire, 1.0kHz res. freq., 4 ohms, 94dB/2.83V

Large ferrite magnet, silk dome, three internal chambers, copper clad alu VC wire, 450Hz res. freq., very low distortion, 4 and 8 ohm available, with or without ferro fluid.