HotSpring Spa This kit is designed for all 1996-current Hot Spring & Tiger River spas. The plastic retainers in this kit come in two lengths. If your pillows have remained in place over the years (you don't find the pillows floating in the spa) then you'll use the white retainers. They gray extensions are used only if your pillows have fallen off often in the past. The retainers are screwed into the spa shell in a recessed area on the lounger (bed) and/or corner seat(s) of the spa. The two round indentations on the backside of the pillow are aligned with the retainers as the pillow is "pressed" into place. Note: If your spa already has these pillow retainers attached, then you won't need this item when purchasing replacement pillows.