Manual breast pumps

Ba

I'm 34 weeks pregnant right now. Took a breastfeeding class last night and wanted to get ahead of the game with milk storage after baby arrives. I will be going back to work 8 weeks after delivery. My insurance covers an electric pump, but I am unsure as to which ones they cover. But I want to have a back up manual for travel and just in case the insurance covered one dies. What manual pump do most of you ladies use and any cons to using it?