Our durable Steel Rectangular Backboards are built strong for rugged playground use 12 gauge steel shell with white powder-coat finish Constructed with an integral reinforcing steel channel on reverse side for mounting and increased board support 20 x 35 mounting centers for attaching board to structure Capable of direct mounting with integral keyhole slots to permanently attach board to post and allow for goal replacement without removing the board Compatible Mounting: Gooseneck & Straight-Arm Posts Recommended Rims: 8550, 5500, 8800, 7550, 240, 39WO For indoor/outdoor use.