Review on iBOLT 25mm to 17mm Composite Ball Adapter for Dual Ball Socket Mounting Arms - Compatible with Garmin GPS/iBOLT 17mm Brackets by Isaiah Edgar

Requires a mount that works with the TomTom GO520 mount. The original mount is suction based. My rig uses a small, solid RamMount grip with a 1" ball mount and 1" extension. This accessory meets my needs. The cradle mount easily separates from the small ball mount. However, fitting a slightly larger ball (17mm) onto the mount required the use of a press-fit compression clamp. Be sure to leave the inner shell of the ball in place (this will ensure a tight fit). Since it's a snug fit, it's best to mount it perpendicular to the mount and leave it there (or whatever angle you want it to be). The snug fit prevents the GPS device from rocking or rocking (ideal solution). The positioning of the GPS device for the display can be done with the RamMount. I've used this on a motorcycle and haven't seen any problems with it coming loose/wiggling.