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