CRG Billet Internal Bar End Mirror Adapter 7/8" CRG Internal Billet adapter for 7/8" handlebars. Use in conjunction with CRG LS 3.2, LS 2.2, Arrow, Hindsight, Hindsigh LS, and Blindsight bar end mirrors! The 7/8" Adapter kit assembly will work on bars with internal diameters as small as 12mm (.475") and as large as 19mm (.750"). This range covers virtually all aluminum and steel bars/clip-ons.