Black / White and Grey .. we just love the Trek Necklace .. 100% food grade silicone and are free from BPA, Lead, Cadmium, Phthalates, PVC and Latex. The beads will not absorb odours or support the growth of mould, fungus or bacteria. They are completely non toxic. Every necklace is fitted with a special safety clasp that is designed to break apart when the necklace is sharply tugged - preventing the necklace from breaking. We use strong nylon 2mm cord designed for these necklaces.