Jarware 82627 Salt and Pepper Shaker for Regular Mouth Mason Jars, Grey

How does this work? Do you get a mixture of salt and pepper with each shake? Also can it be completely closed or do contents remain open to the air?

How long is the inner tube? Could it be used on an 8oz jar instead of 16oz?

will this work for cinnamon and sugar mix?

Purchased this. i cannot get it to work with any canning lid i have. tryed running lid under hot water. still wont pop in the lid. any suggestions?