This small screwtop vial is perfect for making your own special geocaches from. It has ribs around the neck enabling it to grip onto the inside of a hole or gives the person opening the cache extra grip.
The lid contains a rubber ring and has a large internal lip to prevent water from entering. It is slightly longer than other caches of this size and will take a 40mm logsheet. 

It is 50mm long and 10mm wide (lid 12mm wide)