Waterfall Pillow Charcoal 2010-2015 .This pillow is similar to the tubular pillow however this one has an opening in the centre for the Hydropool Waterfall Feature. 

This pillow can be used as a replacement for waterfall pillows on Self Clean Spas and Swim Spas produced after 2010 until 2015

It is held into place with a tongue & groove design on the side of the pillow.