Looking to add 4 GB RAM to my partner's HP ProBook 4535s (she has 1x 4 GB inside already, with 1x slot available).
It supports PC3-10600 (1333 MHz) and PC3-12800 (1600 MHz), according to the Crucial System Scanner.
The least I can spend on the 4 GB module, the better (as long as it works of course, and comes from a reputable retailer in case I have any trouble with the module).
I've found the following module from Amazon: Crucial 4GB SODIMM Spectek Select Memory Module (£15.33 total cost).
It's almost £20 cheaper than any other store/module, so I'm guessing I'm missing something and that it's not actually designed for such a laptop.
If it's fine, then I'm glad, because Crucial and Amazon are both trustworthy in my books.