They are made of our buttery-soft elastic! Which is an elastic encased in Repreve (aka an awesome polyester made from recycled plastic water bottles).
We know lots of folks can be sensitive to metals, so our buckle on the watchbands are zinc alloy since that is durable, nickel-free, and tends to be a better option for sensitive skin. The connectors to the watch are nylon.
**IMPORTANT: ZOX do contain latex, though the latex is typically not visible (each strand of latex is encased in polyester), you may experience discomfort if you're allergic to latex.