This is the LNB FSKUVN, which Maplins sell with their Passion HD package.
The customer had tried to set up the dish himself,but had problems, so I dropped in to do the final alignment.
With the LNB in the usual Skew position for Astra 28.2E, I was getting abysmal quality readings and a very flat spectrum, so I moved it further around until the spectrum improved, but found I was on the opposite polarity.
Well the picture attached is where I had to put it for perfect skew, have included a red line to show where I would have expected it to be.
Edited for additional information. Also similar applies to the
Icecrypt 0.1db single LNB. There is a feint scale on the top of the LNB, but many people will assume that the cable connector should be vertical at the bottom.