Faqs By 

NOS stands for "New Old Stock", so it is a new tube but only old made.

NIB stands for "New in Box", it is a question of new tubes in original box, old or manufactured.

In the case of NOS tubes, the ideal is that it should also be NIB, which in principle guarantees that they are brand new.

A NOS product without an original box can be sold as new, but after a test bench test.

In this case, he still loses his rating.