A couple of different ones but 90% ever seen are RIVCO Passenger footboards with the separately sold
Rivco Products - TR3005-5 - Relocation Kit for Passenger Floorboards
USA
US$72
Rivco Products Relocation Kit for Passenger Floorboards (TR3005-5) - ThumperTalk
US$79.99
Rivco Passenger Board Relocation Arms - TR3005-5
$79.95
Rear Floorboards by Rivco for the New Triumph Rocket III
UK
£97.21
Triumph Rocket III Passenger Board Pillion Relocation Arms
Footboards
Triumph Rocket III Passenger Floorboards Pillion Rivco
TR3005
£363.00
Triumph Rocket III Passenger Floorboards Pillion
Increase foot and leg support as well as allowing for a variation in foot position on long rides. (Shown in pictures with optional Relocation Arm, sold separately).
Made from billet aluminium and chrome plated finish. The soft, antivibration, inlaid rubber pads further insure passenger comfort. They will fold and lock in the up position.
Australia - Get ready to scream!
Extensions
Au$246.40
Triumph Rocket III Passenger Board Relocation Arms [TR3005-5] - 6.40 : Chromeworld Australia Premier Online Sales Australia for Motorcycle Accessories
These are the cheaper steel rather than alloy RIVCOs.


I think these TR3125 are actually aftermarket replacement for R3Touring ones.
Not for Roadsters/Classics.
- Part Number: TR3125
- Manufactured by: Rivco
Au$779.24
Classic Steel Passenger Floorboards for the Triumph Rocket III [TR3125] - 9.24 : Chromeworld Australia Premier Online Sales Australia for Motorcycle Accessories
I think another may have been Maddog, Bulldog or something similar.
Triumph Performance Parts here in in rural Victoria, Australia, has a few options too if you scroll through this page of the R3 accessories available.
Links:
Rocket III
Rocket III Rocket Accesories
They have heaps of other R3 bits but are fairly expensive.
From Rivco Products comes the Passenger Floorboards for the Triumph Rocket III Standard and Classic
These beauties are CNC Machined from billet aluminum and triple-chrome plated. These boards greatly increase foot and leg support over the stock pegs by using anti-vibration neoprene pads.
The images below are shown with the optional solid steel, chrome plated relocation arm which moves the boards forward by 4”. This creates greater comfort by allowing passengers to stretch out a bit more. They’re also great for added clearance when using saddlebags.
NewBonneville USA
Rear Floorboards by Rivco for the New Triumph Rocket III
Passenger Floorboards
$269.95
Shopping cart
Floorboard Relocation Arms
$79.95
Shopping cart
More options:
These can be fitted front or rear. I HAVE THESE 5 POSITION ONES ON MY FRONT 2010 ABS ROADSTER.
Au$407.98
Premium & Ribbed Folding Boards for Driver or Passenger - Chrome
BLACK VERSION
Kuryakyn - ISO®-Board Conversions for Driver or Passenger