Of all the manual breast pumps, this one might be the very easiest to use. you can get an awful lot of milk without your hand getting too tired because the handle is ergonomic, and you can lean back and relax while pumping (you don’t have to lean forward to make sure the milk gets in the bottle). A few people even prefer this hand pump to their electric pump!
Hand pumps have fewer parts to clean and are more portable and quiet, but in general people tend to prefer the labor-saving electric pumps. So the fact that some mothers prefer this hand pump over the electrical one is a big deal.