Nicely found, Andy, and at the best price in the world at the moment -- £0.99 -- though another 5d 20h will likely change that!
For those who might be wondering, the 700C and 26in Extrawheel use the same "chassis" and tongue (fastening fork) assembly; the trailer can be converted simply by swapping the desired wheel size and adjusting the mudguard accordingly.
"29-ers" (MTBs with wide knobby tires mounted on 700C wheels) and Surly's wide-tire Pugsley can be accommodated with longer/wider fastening forks available separately from Extrawheel. Otherwise, the same standard fastening fork accommodates either 26in or 700C wheels.
Best,
Dan.
