known as a Macrovision Scrubber
. Or maybe that's just because I'm old school
Device used to remove the Macrovision interference used on VHS and DVD to protect against copying. An alternate use of it is to improve picture quality of such recordings.
Macrovision Busters, oddly enough, are BUILT-IN to many old models of VHS tape players to improve the quality of playback. It wasn't until the MPAA wanted to use Macrovision to protect their asse(t)s that it was suddenly illegal.