We get the rubber for Gurus from trees! In a process kind of like tapping maple syrup, natural latex is harvested and processed by hand from rubber trees. This process can continue daily for 25 years without harming the tree. Using primarily natural rubber makes Gurus biodegradable and much better for the environment than traditional plastic or foam flip-flops and sandals. Natural rubber makes Gurus the most comfortable pair of sandals you have worn. The sole cushions every step and will form to your feet over time. Because Gurus come from trees, we plant a tree for every pair we sell.