I purchased a few of these a couple of years ago, for our TVs and to give as gifts. I only wish they had the Tetrabyte size back then. These are super easy to hook up to your TV cable box. What it does is give you more room to record your favorite TV movies and shows off of your DVR recorder. Where you might only have approximately 70 hours of recording space on your DVR, this will give you so much more. I think mine was 500 MB, and it gave me a total of 300 hours recording space. I often come close to using it all up with the movies I record, so the 1 TB or higher versions would be a better buy. Plus, they are less expensive nowadays (as electronics usually are). This costs less than I paid for half the space. I know this comes too late to purchase online for Christmas, but maybe you can find them at a local electronics store. Or just treat yourself to a New Year's gift and order online.