"Works Great - It's what you need to expand capacity !!"5.0 starson by Terablogger
Pros: Works Great with my DirecTv HR-21. Has all the features you need. The Right Hard Drive (multimedia) The Right Case (Passively - QUIET cooled), Quality eSATA cable for Sata connection. Not easy to build your own unit, due to special parts needed.
Cons: Some places sell for more than list price. Check prices carefully. When I see a 1 Terabyte unit on sale, I'll buy that, and pass the 500 Gig to my son.
Summary: Works with DirecTv
Certfied by TiVo for their HD Units.
Reported to work with newer Scientific Atlanta units.
Just connect eSata cable, plug it in, turn it on, and reboot the DVR.