Difference beetween H10L and H10LK?

I can only find the H10LK where i live, and the specs appear to be the same.
So just for my personal knowledge - what is the difference beet “L” and “LK” (like with H10NK, H10AK etc.)

And also, what is BETTER - the H10L or the H20L?

I think the K difference may be a minor (bezel, color…) difference.
The H10L uses a Renesas chipset and is based on the H10N with 12x DVD-RAM, while the H20L uses a Panasonic chipset and only does 5x DVD-RAM.
But the x2xx series burns can be scanned accurately with a BenQ (and are possibly more compatible than the x1xx series).

Wich chipset it better?

The extra “K” at the end is probably used for bezel colour or whether the drive comes with bundled software. I think shops add these extra letters for stock taking purposes. When you get the actual drive and look at the model number printed on the label of the drive, you will see there is nothing apart from “H10L” printed on it.

As for which chipset is better, I don’t think anyone can answer that. Both seem to produce good results in terms of burn quality.

are you sure it’s not H10LBK? the BK sometimes stands for Black.