I am from a company called Zerosigma, We repair and calibrate all brands
of pipets. I have been doing this for a decade now. And from my experience
I can tell
that Rainin pipets, although expensive are the best. They are more
accurate, and stay that way for long periods of time. Some of the cheaper
pipets are just that.
If you are looking for a positive displacement pipet, Eppendorf is a