Full-duplex playback and recording. Built in 16-bit CODEC Built-in 32 OHM Earphone buffer Supports multi-channel output to 2 or 4 speaker systems HRTF 3D positional audio, supporting both DirectSound 3D & A3D ACPI compliant power down management Design to fit in low profile or standard height chassis 4 Channel 16-bit DAC PCI Rev. 2.2 compliant with bus mastering modes PC98/99 specification compliant