Applying the screen protector is simple if you know what you are doing. Start by giving your compass a good clean! We like to start with removing the black tab along with the top film its stuck to. This makes it easier to take out the circles that are not used and also the big ones that are used as seen below. (It is easy to identify the top and bottom screen protector as the bigger circle is the top to allow for the lens. keep the two slightly separate and apply one at a time)
Remove all the smaller circles and throw them away but keep the bigger inner circles and put them straight on the top and bottom of the lens as shown below.
Now with all the circles removed you can take off the red tab along with the film it is stuck to and reveal the adhesive side and carefully apply it to the compass making sure it is straight.
The bottom screen protector will have some air bubbles because of the engraved lines and numbers but this does not cause any problem and you can work it into the lines and it’s basically unnoticeable.
These screen protectors help a lot with preventing scratches on your delicate compass and it won't become unreadable!
In conclusion, if you want the ultimate full protection for your whole compass then it is best to have both these forms of protection and you can find them here!