Photo of the SONU Comfort Insert Pillow in dark grey fabric on a black background.
The SONU Comfort Insert fills in one side of the Comfort Channel, making the SONU Sleep System more akin to a flat mattress, but still with some give for your shoulders. This versatility can be helpful for couples who sleep differently from one another (e.g. a side sleeper and a back sleeper) and for those who simply prefer less space in the Comfort Channel.