Boss/Co-worker gift

Hey guys.  I was wondering if you all had any suggestions for some gifts I could get several of my bosses and co-workers.  I work in retail and am in a position where there is usually only one of us in the position for six hours a day.  So when I have to pump someone has to cover my position.  I have three bosses and a few co-workers that always cover my pumping sessions without complaint and are pretty quick to help.  I know that it is my right to be able to pump but they cover my position without complaining when they have their own work they need to be doing as well.  So I feel pretty guilty asking them twice a day, five days a week.  I want to show them that they are appreciated.  Especially since I have a few co-workers that think I am just using my pumping time to be lazy.  And my amazing bosses/co-workers are all male, with the exception of one female, and I feel males tend to not be as understanding when it comes to pumping which makes my co-workers that much more awesome 
Thank you all for your time