I have one almost identical but under a different name.
That type of grinder will NOT produce a fine powder, despite what the advertising says, it is ok for coarse or medium grind but that type of blade grinder cannot produce a fine grind, for that you need the type that uses ceramic grinding wheels.
If, as you say, you are using a cafetiere then you do not need a fine grind, medium grind is ideal.
The pressure type of coffee machines (the ones used in cafe's etc) does need a fine grind, in order to extract as much coffee flavour out of the beans.
When using a cafetiere, the strength of the coffee beans is more important, I try for a high strength rating of 5 or more if used to produce cappachino or latte style coffee, anything below that strength and you don't get a full flavour coffee – all my opinion of course, others may differ.