The Brunton 8099 type compasses are seriously flawed in design in my view. A bubble of any sort will prevent the compass card from rotating....effectively making it useless. That coupled with its tendency to form bubbles at the drop of a hat has relegated mine to the storage box....after 3 capsule replacements it just is not trustworthy.

A bubble in a needle compass will most likely not make the instrument useless....that to me is the reason to not use any of the Brunton compass card type instruments.