Is this a deliberate cover-up? What connecting cable is that? A bit technical this one.
I have one of these Sunpak G4500DX hammer-heads (also sold as the "555") and it offers camera dedication - but only with a special module on the camera hot-shoe, connected to the unit with a proprietory multi-core cable with a multi-pin plug.
But you could alternatively connect it to the camera's X socket with a simple cable, with no dedication of course. In that case it is no better than the cheaper G4500 (without the "DX" =de-luxe?).
It looks to my practised eye as if the cable with this one is the simple X socket version. Nothing wrong with that if he were up front about it, but that it looks as if an attempt has been made to conceal the type of cable by covering it with the bracket. Why else would you put the cable awkwardly half-under that bracket for the photos? He also says it is for Canon, but there is no dedication module in the sale.
The special connecting cables for dedication can be hard to find and are not cheap if you do. The dedication modules are more common (as they were also used for shoe-mount units) and cost about £10.
sunpak G4500 DX flash gun | eBay