KeelanClarkThe slot is made to create extra loft if you want it. Whether it be a shirt, hoodie, inflatable pillow, etc. But it was not built to spec specifically with a Klymit pillow. But yes the pillow x series will fit. Put pillow in first, then blow up till comfortable.
KlymitTannerI have the large Klymit X pillow. I take it that will definitely not fit in there.
It would be awesome if they were made to go together because right now I attach a small down pillow on top of my Klymit to add some lift and softness. It slides off all the time and drives me crazy.