I had a replacement AC adapter for my MacBook Pro that I didn't have an extension cord for. I decided to link it to that. Since I don't have a regular cable for it, anything is better than nothing. The quality of the cable is clearly not up to OEM standards. It's thinner but tougher. The "duckhead" part that fits into the power adapter is definitely not the right color or texture to match Apple's white plastic. But for the price I don't care as it's just a replacement part. There is a ground spring in the duck head that connects to the ground pin of the plug. This is an important safety (and RFI) feature, but it's easy to overlook when it's cheaper, so it's good that this cable gets it right.