How to know laptop memory speed/clock?

I'm planning to buy another memory card for my laptop (Lenovo G400-0670) but I don't know the clock speed (PC12800 or other) of the current memory card. I've tried using crucial.com's system scan and CPU-Z by CPU-ID but none of them gave me the information I need. I've tried googling but the results only consists of selling or buying the laptop.

Then open the memory door and remove what you have and read the stickers on them. Then google that info for the specs.