KNIT OUTER SHOWN SO YOU CAN SEE THE SHREDDED RUBBER. These pillows are made of USDA certified organic rubber that has been processed naturally into usable rubber. We shred by hand here for a great feel and then put in a durable non-removable woven outer, it is fully washable. The loft is adjustable without taking the pillow apart; you can move the natural rubber just as you would a buckwheat-fill pillow, but this pillow has a softer feel! Many “natural” rubber contains toxins such as benzene, toluene, phthalates… Ask for test results specifically for those common rubber VOCS. Our pillows use the best rubber with high purity standards. Ours is Dunlop as the Talalay rubber has petroleum added in the form of artificial vanillin so we will not use Talalay.  The vanillin in talalay contains dimethyl sulfate and is highly toxic according to a Virginia University study.