The CFW-9 is essentially the same size and shape as the current CFW-8A to match the ST series camera body when directly bolted to the front. They are difficult to tell apart by simply looking at them.

The CFW9 has the same capacity of five 1.25" filters so there is little practical difference in the two except that the CFW9 plugs into the I2C-AUX port on the cameras instead of the AO/CFW/SCOPE port as the CFW-8A does. This also means the CFW9 is not compatible with older parallel versions of the ST series cameras ... it will only work with ST cameras that have USB electronics.