The bamboo mattress cover is made from a renewable resource, which is good news for environmentally conscious consumers. In the manufacturing process, no chemical is added and the fabric is naturally hypoallergenic and antibacterial. This mattress cover is waterproof and will extend the lifetime of your mattress. Since bamboo is less permeable to odors, the period between the washes may be more distant. The gussets are up to 18 inches. The elastic goes all the way around. Washing machine safe.