The footprint size of the base is essentially the size of an iPad to give you a guide and reaches to 260mm/10.25" in height.  When the iPad lays flat the height is 135mm/5.3".

The base is secured with concealed screws that are only accessible by unclipping the upper casing and rotating 90 degrees.

The tethering cable solution has a very versatile anchoring solution. Depending on whether you want this to be a permanent or temporary solution determines how the tether is secured.  The optional anchor plate comes with a permanent and semi-permanent installation option. 

Look in your kit for the security tab. Follow the instructions supplied within the kit for the security tab installation.