What size is the ball mount on a Garmin GPS and how do I find a compatible mount?
Amazon.com: ThtRht 2 Pack Double 17mm Ball Mount Joint Head Connector Extension Adapter for Garmin GPS Car Bicycle Motorcycle Handle Bar Phone Tablet Holder Bracket Socket Arm Base Dash Camera Clip Clamps :
DIY Poor Man Gps Mount V. 2.0 for Garmin Geko - Instructables
17mm Ball Mount to Diamond ball joint or Square Mounting Base for Phone GPS Holder Mount Ram Mount Garmin Zumo/TomTom - AliExpress
DIY: ENVE/GoPro Dual Mount — life is a beautiful detail