Link
Note: If you already have Pro Tools TDM 6.9.2 or higher or Pro Tools LE 6.9.2 or higher installed on your system, you should not use the Standalone Digidesign CoreAudio Driver installer.
The Digidesign CoreAudio Driver is a multi-client, multichannel sound driver that allows CoreAudio-compatible applications to record and play back through the following Digidesign audio interfaces:
Pro Tools|HD Accel
Pro Tools|HD
Digi 002
Digi 002 Rack
Mbox
Note: If you already have Pro Tools TDM 6.9.2 or higher or Pro Tools LE 6.9.2 or higher installed on your system, you should not use the Standalone Digidesign CoreAudio Driver installer.