Gurus are made primarily from natural rubber that is sustainably sourced from trees. Everything in our sandals is completely eco-friendly. We also use environmentally conscious packaging. Unlike traditional flip-flops, our adjustable ankle strap twists to fit all ankle sizes and secure sandals even when jumping! Just pull the plugs from below and rotate your strap to make the foot hole larger or smaller. Our plush natural rubber sole is thicker than most flip-flops and molds to your feet over time for added comfort. They almost feel like walking on a pillow!