The minimalist design, which contains the essential necessary technology to make this device a smartwatch is great. The materials are excellent. Even the battery seems to live up (you can do a day safely) despite the many bad comments in the web. Do you want to give a touch of personality to your moto 360?
From here you can download the drawing done with SketchUp 2015. And from here the .stl file directly.
Below there are some pictures of my yellow bumper made up of PLA. You can pick any different materials/colors.
This work is distributed under License Creative Commons Attribution - NonCommercial - NoDerivatives 4.0 International.