Very unique and interesting Stanhope.  The key looking device has wear to the metal coating, but once you look throught the glass the image of London architecture is perfect to the eye.  'Souvenir of London'
You can easily push down onto the top of the device whilst resting your other finger on the rest which sits halfway down.  Out pops a small grabber, I would imagine was meant for a jeweller and their small gems.  Historical wear, but still a great piece of London Memorabilia.  It measures