Because the main prat of the vacuum interrupter is china, which is fragile, so they need more strong packages. First.  We customize some foam according to the size of the vacuum interrupter, the foam will be cut into two part. When pack the goods, we put the bottom part of the foam into the box and the put the vacuum interrupter which has been put int a plastic bag into the foam, then put the other part of the foam to the box, the products will be surround well by the foam, so the foam will protect the products very well.