Wholesale | Box of 4 Kapok filled Yoga Bolsters Yoga Bolsters to support you in your Yoga and Pilates exercises. The inner cover has a zipper and the outer cover a zipper and carrying strap. The bolster is filled with the finest Kapok from Java, Indonesia. Kapok is a natural hollow fibre and therefore very light and voluminous. Over time, this may compact and settle. Perfect to support you in resorative Yoga postures, or postures requiring gentle support, perfect for 'heart opening' work.