I have the older version of their adjustable (which is like the single pump one on their site but with an adjustable top vs. the fixed 3bar or 4bar they sell now). I have it mounted using the bracket on the firewall, but may be moving it. Car hasn't moved in forever. It is about the size of a large grade A egg. I would say a third smaller than the Aeromotive it replaced.
THis, but adjustable:
Brent