a simple sleeve with a flat side so it can be mounted to surfaces easily, hiding the bare button. the button is an E-Switch model LP1OA1AG (https://pixhawk.org/users/safety_switch)my first print at scale ended up just a bit too small, found 1.1 scale was just right - button slide in easily. a small spot of hot glue will keep it seated just fine, while keeping it removable.