Why you may need this:If you upgrade to an SSD* it's a good idea to repurpose your old spinny drive as a second Hard Drive on your computer. Not all data benefits from being accessable from an SSD.In order to do install both HDs you'll need 2 Sata data cables and 2 Sata power cables. The data cables are the smaller of the two. Each drive has a data cable connecting it directly to the motherboard (the connectors on the motherboard are probably numbered. Your SSD should be the #1 drive HHD will be #2).The power is a different story. On my computer power for the optical drive and hard drive came off the cable. This product is a splitter that allows you to power more Sata devices.They will all still need their own data cable but this cable takes care of the power for this drive as well as a couple more if you ever want to install a third or fourth HD or DVD player, CD burner ect.*****(which you should, best money you'll ever spend on electronics by extending the life of your older PC by a couple years at least. It really is that good. Don't buy a car new computer until you try upgrading to an SSD Boot Drive first. If you still feel compelled to buy a new machine you'll have the new SSD to install into the new one)TL/DRExactly as discribed and delivered quicker than expect, as usual. Cable does exactly what I need and has been working fine for 4-5 months.