Our BMW Bar Insert allows riders to use Flexx Handlebars or most aluminum handlebars with all of their stock controls mounted as BMW intended. To mount the stock bar end weight/cap and grip components on '06-'13 BMW GS/GSA our BMW Insert is required, as the stock bars are either threaded or have an insert to bolt the bar end weight/cap to the bar. The bar end weight/cap supports a portion of the of grip tube as the grip and throttle tubes protrude from the end of the handlebar.
Please note our BMW Inserts do not work with GS 1200 LC, for that application our Threaded Bar Mounts are recommended: http://www.fasstco.com/products/threaded-bar-end-mounts