'conditional' text behing price on productpage

On a product page, directly after the price of a product, I want, for some products, to add text like ‘for two pieces’.

I managed to get it ‘hard coded’ in the template, but now, off course, it shows on all product pages. Therefor I need to make it ‘conditional’: if it is product ‘X”, add after price “for two pieces’, if not, do not add anything…
So far the logic, now the code. No clue. Can anybody help me out here?

txs.
very much appreciated.