I forgot to post this. The oil is made by a company called Sta-Lube in the USA and may not be available in Europe. There is nothing special about it and other companies make similar oil.

From their website

GL-4 Hypoid Gear Oil has low pour points and high temp properties to provide lubrication over a wide temperature range. This versatile lubricant contains anti-rust and anti-wear EP additives to provide the corrosion protection in drives and hypoid gears. It is not corrosive to copper, bronze, or other non-ferrous alloy bearings and bushings.

If touring I don't use gear oil as I don't want to have to carry another oil and use 50W motor oil. But still have to carry ATF for the primary!