For my 180 cm Channel Master Offset disk I wanted to buy a set of conical scalar rings. Living in Europe there are some things to consider: 1. Prices in Europe are sky-high while postal rates are minimal 2. Prices in the US are much lower but postal rates to Europe tend to be absurdly high 3. In China I can order such rings for US $6,99 plus relatively cheap postal rates to Europe. However, are all conical scalar rings the same or are there big differences? When using a severly limited size dish the last thing you want is suffer unnecessary extra losses. Does it make sense to order at a place like Alibaba or would I be cutting myself in the fingers doing so? Personally I'll use it for C-Band only, but a friend who uses the same dish with a C/Ku LNB intends to use one for his installation too. I do wonder however what such scalar rings intended for C-Band reception improvements would do to his Ku-Band reception. Is there anyone who could give me some advice in this matter?