Easy to use. There is a black tension nut on the sides of each section. Tight fit when stored, loose when in use. I don't understand how people have this problem lol. Also, the numbers are the exact font size of the text on my phone. They are also laser engraved. Without a stamp because you can see that the print is sticking out on the other side. Apparently not printed either. There is a whitish spot on the back of the inscriptions. This is what happens when heat is released on galvanized metals. It is in order. These sensors are perfect and exactly what I expected.