As ZRX61 answered - C.K.
Although originally German, they are I believe a British company now. They supply a lot of British hardware shops.
Unlike some of these distributers though, they seem to take the trouble to have some decent tools made for them, generally in Germany, though there are some cheaper offerings from Taiwan too.
I believe their “Classic” screwdrivers are made by Heyco, and yes, in my experience too, they are very good quality. Most of my nut runners are C.K. My absolute favourites, bar none.
Below are the contents of my “road box” (well, as it was a year or so back). A right mix of makes but all tried and tested. C.K. drivers top left!