OEM Systems RIB-LCR Rough-In Kit for SELCRKE, AP525LCRS and PS525LCRS: * Mounting straps span 24" members * Dome/mounting flange slides along straps * Substantial friction holds ring fast * Inexpensive * Versatile * Wire inlet * Shields speaker for insulation * Metal straps span 16" centers * For all dual 5-1/4" rectangular speakers * Mouth opening: 7-7/8" x 14-7/16"