Replacement button for the garmin edge 1000 and 1000 explore with a rubber o-ring. I used the smallest 3x1.5mm o-ring and pushed the button in from the outside until the button sat flush with the case. Push force should be enough to activate the button but not enough to squish it in as the rubber will keep the button in place. This should also be weather proof but cannot say for sure until I test it further. Also try to use a more stretchy and softer o-ring since they will last longer than cheap chinese ones.