I have one of those and it cost me about £6 some years ago of Ebay. Mine was made in the USA, but I do wonder at times. £1.99 has to be worth a punt. I use mine on lure hooks mostly, all other hooks it seems easier to just change them.
This is exactly like mine Mark, same as the Lidl one, but all silver.
I can tell you, they make 'diamonds sharpeners' sound like really expensive items, as if the diamonds were actually worth anything. I used to have a client in Crawley, Asahi Diamond, that made this stuff and the contact took me around part of the factory one day. He put a small pile of these diamonds in my hand and asked how much I thought they were worth. I hadn't a clue, but it turned out there was about £2 worth in my hand and it would have made about 50 of these sharpeners.