SIIG Eide Ultra Ata-133/100 Pro Controller for Mac High-speed dual channel Ultra ATA 133/100 controller for Mac Direct support from Mac OS X (V 10.1X) or later Works with various brands of Ultra ATA 133/100/66/33 hard disk drives Auto-detects drive types and fine tunes to the best performance for each Ultra ATA drive Provides two independent Ultra ATA channels for faster data transfer