Three connectors for up to two devices. It has 80 wires 39 pins, which makes it backward compatible. This means the cable will work with an old ATA33 hard drive/motherboard/CD ROM. Check the IDE connector on your motherboards. The connectors are color-coded for ATA133. The blue connector is for the motherboard. The black connector must be connected to the master hard drive. The middle grey end one is for a slave drive if there is one. Copper shielding cables ensure faster, more reliable data transfer rate and minimize EMI Minimal clutter inside the case and better air flow to efficiently cool Pull tab at each connector for easy installation Pull tab at each connector for easy installation For Ultra ATA/100, Ultra ATA/66, Ultra ATA/33 and DMA, and with EIDE/IDE hard drives & CD-ROM drives Round cable design increases air flow inside case Color: BLUE Length: 24"