We also pay close attention to things like dust, water, and exhaust-oil resistance. How? Through the use of 13 O-rings for sealing. Why so many? It's because truly protecting the insides from the environment means using there must be an O-ring everywhere, at the splined output shaft where it exits the case, where the three case components come together to become one, and even beneath the 10 individual screw heads!
For example, what if while you're flying a pop-up rain shower develops before you can land? Or maybe you love to fly off water! This means protecting the servo's guts from the environment is important, right? After all, we know how pernicious water can be with respect to getting inside the servo. And this is important for all users . . .even if you never intend to take your servo underwater! But if you do plan to play submarine, then read the askJohn article regarding how to make them more water-resistant with a couple easy steps.