I have just fitted a Morgo Filter to replace the Norton type that was fitted.
The Norton unit was springing the toolbox lid, and does take up a lot of the available space in there.
The Morgo is on the expensive side, but is a beautifully made item. It is light weight, and fixes with a single 6mm set screw. It has two rat tail pipe connectors as standard, with optional extra banjo fittings. Filters are readily available (HF197), and nicely compact.
I ordered mine around 2pm Wednesday, it was delivered by lunch time Thursday.