Premier Pools 2890-52 52" Metric Straight Step to Radius Wall Panel Adapter Kit - This 52" Metric Straight Step to Radius Wall Panel Adapter Kit is for use with Radiant Metric pools. Position the female stair connector on the step flange, making sure it is level and meets the top of the pool panel. Hold in place with vise grips or c-clamps. Using a 7/16" drill bit, drill through the step flange at the holes in the female stair connector. Bolt the adapter plate on to the step flange using the backer washer and nut on the inside of the step flange. Attach the male stair connector to the female stair connector at the ball joint. The extended t-spline is installed on the exterior side of the pool, with holes to attach the a-frame components. The 10” standard spline is installed on top of the t-spline. The 52" standard spline is installed on the interior side of the pool.