The CN1 mounting arm features two 2Ó by 3Ó (51 x 76 mm) rectangular extrudedaluminum arms welded to the central pole adaptor. The mounting arm includes a cast-aluminum decorative curved section welded to the central pole adaptor and the arm. The luminaire adaptor will accept a luminaire equipped with LumecÕs four-bolt mounting system.The central pole adaptor slip-fits 12Ò (305 mm) into a 4Ó (102 mm), 5Ó (127 mm) or 5 9/16Ó (141 mm) O.D. pole or tenon.The CN1 is available with the OV option that can accommodate up to two 175W ballasts.For pole supplied by others, we strongly recommend the OV option.