Size is pretty similar to the original iPhone. The actual screen is the size of a credit card. You do not really notice the size once you get reading. It is light enough to be carried anywhere.

But you need a strategy to protect the screen which is the most delicate part of the entire assembly. They do sell screen protectors of various kinds and even supply one in the original box. I bought their magnetic case which works for my use case (I do not store it in a pocket with keys and other objects that might damage the screen).

One of the main idea is sticking it on the back of the phone so it must be smaller