The slipper warmer will gently mold to the contours of your feet to help relieve sore muscles and stiffness. Simply heat the whole slipper in a microwave to help shake off those aches and pains. May help to relieve headaches, tension and anxiety. Outer cover is made of fleece. Insert filled with natural grains and pure lavender. Outer cover can be removed and cleaned per instructions. Follow heating instructions. In time aroma may need replenishing, add a few drops of lavender pure essential oil onto the cushion after heating