... , FDA, NSF, WRAS, etc. Details of silicon rubber seals for glass bottle:1. Materials: comply to ROHS, Silicone (VMQ), or NBR, EPDM ... . Tolerance: strictly upon international standard, no flash.5. Color: black, transparent, green, red, yellow, grey, purple, pink or as your requested ... on your idea. Good Insulation Property Silicon rubber seals for glass bottle