Shown with the pink bottle pocket I’m also selling, and on the Art Kanken I’m selling (with and without the rainbow chest strap which I am, you guessed it, also selling!) These give more comfort and support when wearing the backpack. Recommended not to wash (don’t immerse in water), but can spot clean with wet cloth, and then dry with another cloth. Feel free to bundle with the other Kanken items I’m selling if you’d like, and leave me an offer!