Twenty-Three Octave multi-mode voltage-controlled oscillator
http://www.noiseengineering.us/sinc-iter
The depth of this module is far less than stated on Noise Engineering's webpage - it's only 27 mm deep.
EDITED Dec 15th 2016, 17:29
Own this thing, I use it to drive more low end on my most basic patches.
Mutable Instruments - TipTop Audio - Intellijel - Noise Engineering - Doepfer - WMD-SSF