Radiant Pools KS-52-RWSA 52" Metric Stair Adapter Kit with Spline Attachment - This 52" Stair Adapter Kit is for use with Radiant Metric pools. Assemble the stair adapter kit to the first pool panel with the standard 52” spline on the interior side of pool and the extended t-spline on the exterior of the panel. Position the panel butting up to the step flange and mark the location of the spline stair adapter with a marker or piece of tape. 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.