Shimano bm dn100 battery mountthe bm dn100 battery mount is ideal for use on frames that are running shimano di2 components externally this mount is specifically designed for the new bluetooth sm btr1 battery which gives earlier versions of di2 the feature of being able to change your shifting preferences wirelessly features former di2 generations go wireless with this new mount external mount holds new wireless bluetooth di2 battery e tube technology allows you to change your shifting prefer