they look like the silenced ones to me... below is lifted from the Horsham website.
The H-Dev silenced de-cat pipes give increased performance - on our test car we found a gain of +10bhp and +8ft.lbs torque.
They are silenced but are still make the car slightly louder than the standard cat pipes.
Because these pipes do not have a catalyst core they will not pass an MOT. Also the check engine light will come on due to "low catalyst efficiency". The check engine light issue can be resolved with an ECU remap
These pipes will fit the 2003-2007 cars with the 276 or 297bhp engines, single air box. They will not fit the 2007+ 313bhp twin air box engines or the 370Z engines.