This case is especially designed for protecting hydrometers in the field. It is made of rugged polyvinyl chloride plastic (PVC) for durability and light weight. The fitted cap has a tight grip and is attached to the body of the case with a keeper cord which secures the cap. It is also easy to remove this from a carrying by the cord.
The inside of the case is lined with felt that will protect the instrument. All lining material in the body can be removed for wast cleaning or replacement.