Motorcycle 13.3-14.7mm Fork Stem Yoke Mount & IPX4 Waterproof Case for Samsung Galaxy S4 GT-i9500 Central Fork Stem Yoke Motorcycle Mount with IXP4 Waterproof Case for the Samsung Galaxy S4 GT-i9500 smartphone. The Ultimate Addons central fork stem yoke mount has been developed for use on motorcycles where a handlebar mounting option is not possible or desirable. Designed to fit sports, super bikes, endurance and touring motorbikes using the cylindrical bore wall (steering head tube) of the fork stems. Please check that the stem cover can be removed leaving a central hole for the mount to fix in. Fits holes: 13.3-14.7mm (0.52"-0.58"). The mount is attached to the soft case via the custom made adaptor which slides on to the 3-prong fixing on the reverse of the case. The IPX4 standard waterproof soft case is light-weight, slim and offers protection from dirt, dust, damp weather & water splashes / light rain showers. When mounted the case can be turned 360 to be viewed horizontally or vertically and features a touch sensitive front lens and double zip access.