As per Geoff997's post , I have one of these which I will sell. It is pretty much as per Type911UK's photo above, except that it comes with the protective sleeve for the cone, just to make it a little less susceptible to dust and water.
I think it is fairly accepted that on it's own it is not going to produce any meaningful increase in power. However, it did seem to me to increase responsiveness.
My unit is effectively brand new - it has done less than 20 miles.
A short background to why it will be available:
I bought this K&N Unit together with a switchable sport exhaust, a few weeks ago, and had them both fitted together, and here's the problem: On it's own (with the exhaust switched off) the K&N sounds really good. However, when the exhaust is open there is something about the resonance of both my particular exhaust and the K&N together which was truly awful and, under full throttle, it sounded like a rusted out Morris Marina with a fist sized hole in the exhaust. I took the car back to have the K&N removed the very same day I picked it up.
I say again, had I not spent out on the exhaust, and had only fitted the K&N, then I would have been really pleased with it. But one of them had to go. And given that I was throwing some money down the drain, the cheaper option was to remove the K&N rather than the exhaust.
Let me know if you are interested. I paid £365, but obviously it is now technically used, although you wouldn't know it. I am North side of Crawley.