Siemens SN26M253GB

I have just bought this dishwasher. Our previous one was a Bosch with the blue inlet hose. I always had to use a 2.5m hose as our supply tap is that far away from the dishwasher position.
This Siemens has a different water supply, the pipe is enclosed in a grey plastic tube along with some wiring, to a water shut off valve at the end of the pipe. The pipe is too short to reach our supply tap but the picture diagram of how to connect it shows an extra pipe section 2.2m long which screws onto the end of the supply pipe with an adaptor. It has two straight ends, unlike the standard blue pipes (1 x straight end and 1 x angled end).
I`ve no idea what this pipe section is, as there is no explanation, just pictures. If it could be used it would mean that the water shut off valve would be half way between our water supply tap and the dishwasher.