I normally do not care for stuff NIB (new in box), as I like to dive with all my gauges, even this piston one.  It always seems a shame to take a vintage scuba item out of the box new and dive it.  This gauge is not dived and I hope to find one that is not NIB so I can try it out.  Normally I will not but NIB stuff, but this was gotten for a very good price from someone who wanted to see it in the museum, but chooses to remain anonymous.