I dont know how many ways I can say, I loved this book sooo much. When I was simply trying to understand the Maxwell's equations, this book saved me. Guess what, this book would refresh concept even from the very basic vector dot product, cross product etc, so there is no chance that, the reader will find some concepts inaccessible. It covers what is divergence, what is gradient, what is Curl etc (even though, I would recommend the reader to get the concept of Divergence, Curl, Gradient cleared before reading this book; the reader can get those concepts from Khan Academy online). This book explained well 'what is path integral', 'what is surface integral', 'why there is a circle sign in the middle of a integral operator' etc.
Anyway, I wont believe that, someone who understands calculus, wont understand maxwell's equations even after reading this very thin book with very less effort. The reader does not even need to be a master of calculus. If a partial derivative and Integral operator makes sense to the reader, he/she will find this book accessible.
In the last chapter, (chapter 5), the author derived the Electromagnetic wave equations from maxwell's equation. That part was the most exciting part for me as I was simply waiting for learning that. If the reader knows that, a Wave Equation can be expressed in second order partial derivative form, then, this chapter will makes sense. This book did not explain where and how we got the Wave equation using second order partial derivative. I think, the author could explain that in a paragraph by writing few lines. As I was already familiar with wave equation, I did not have any problem understanding that part. Anyway, I find my every penny worth and I feel myself fortunate that I bought this book.