The CompSight replaces your gun's existing front bead. The low-profile steel base accomodates any one of three crimson or four green interchangeable LitePipes in .090", .105", .115" and .135" diameters and one white "bead". Five different sizes of mounting screws are included in each package to fit most ribs. The full array of LitePipes is organized in a quick-acess carrying case to allow rapid LitePipe changes to match varying light conditions mid-match, machined steel base for durability.