Chinese style hard yellow tofu. In Thailand they have Chinese red stamps on them, like this one with an airplane. The closest thing in the West are the ‘extra firm’ variety you can get at the grocery store. Make sure to drain it really well and pat it dry before cooking.
Storage: Fresh tofu expires very quickly. Make sure to keep in the refrigerator, and use within a couple days of buying, If you buy a packaged variety at the supermarket, make sure to use before the expiry date. If you don’t use it all, store the rest in water, and use within a day or two.