Waterproof Motorcycle U-Bolt Mount for Garmin Nuvi 2559LM (31096)Ultimate Addons Metal U Bolt Handlebar Mount: Fits handlebars 16mm 32mm. Supplied with TWO sizes of u bolt & TWO reducing collars to fit most handlebars. Fully adjustable The IMPACT CASE is held on a ball & socket adjuster which provides 360 degrees adjustment for the perfect viewing position. Your SatNav can be viewed horizontally or vertically, ideal for phone, satnav & map applications and your chosen position is held in place with the easy to use