I have used it many times with Mac OSX10.4 (Tiger) and with OSX10.5 (Loepard). 

The unit comes with a CD-Rom with Formac software version 3.04 and it can still be upgraded to version 3.6.2, as I did for use with Leopard.

I have not used the device with a system running OSX 10/6 Snow Leopard.

This is a versatile box with many uses, all covered in the included manual.

The unit is in good working order. 

Comes with everything pictured.

IT SHOULD BE NOTED THAT THE UNIT DOES NOT NEED, AND DID NOT COME WITH, AN AC POWER SUPPLY. PLEASE SEE PHOTO, TAKEN FROM THE USER MANUAL, THAT ADDRESSES THIS. IT IS POWERED BY THE FIREWIRE 400 CONNECTION FOUND ON MANY MACS EQUIPPED WITH G3 AND G4 PROCESSORS