The profit levels on garden equipment is very low.
So manufacturing can only be sustained by very large production runs to get the most return from the tooling.
Thus nearly every item you buy will have an identical looking model with a differnt brand.
While being made in the same factory with the same tooling and looking similar, usually the cheaper ones are just that, cheaper.
Cheaper inition modules, cheaper steel ( lower grade ) , no heat treatment so gears wear out sooner, no grease seals, etc etc etc.
Unless you can see a greasy residue around the head or the head is noisy & sloppy, no need to worry about greasing it.
If you still want to the they usually take 00 grade grease which will come in a tube and has a consistency of toothpaste.
I have used 2 tubes in 3 years as a small engine workshop and these went into very old trimmers that had obvious leaks.
