RAM Part RAM-B-149Z-300-1U : Heavy-duty Magnetic Plate for GPS, PDAs, and Radar Detectors.

Includes a rectangular 50mm x 38mm x 0.08mm thick metal plate with adhesive back if needed.  The back of the mounting plate has 2 super heavy duty magnets that keep your device in place (we always suggest you tether your device as well).

This mounting plate will attach to the included heavy duty metal mount made of power coated marine grade aluminum.  This fits handlebars from 3/4 to 1 inch in diameter. Fits handlebar diameters up to 1.25 inches.