That's Ampex VRX-1000, the world's first commercial videotape recorder. It debuted in 1951 at a cost of $50,000! http://www.realtechnews.com/posts/2012 (via Unique Daily)
What's so special about this clock? Designed by Benjamin Franklin (when life's pace is slower than it is today) it only has one hand and measures time in 15 minutes increment! Link