8TZ CR Metal heavy duty airtight & waterproof zippers for dry suit, diving suit, immersion suit, chemical suit etc. The metal airtight zipper is a professional product used in high-tech fields. It is made of a slider which engages the inner teeth of the two tapes, and the elastic tape is compressed by the outer teeth to form a completely airtight state. The external liquid, air, gas, water vapor, and dust are isolated with flexibility and operability. Mental airtight zipper is one of our best selling products, is popular in all over the world.