A zafu is a round cushion traditionally used in Zen meditation. It provides support and comfort for practitioners sitting on the floor, helping to maintain proper posture during meditation sessions. The cushion is typically filled with natural materials like buckwheat hulls or cotton, allowing it to conform to the user's body. Zafus come in various sizes, colors, and designs, making them suitable for different preferences and styles. They are often paired with a zabuton, a larger rectangular mat that offers additional cushioning for the knees and legs. Together, these items create a comfortable meditation space.