The Spectra pumps (S1 and S2) are hospital grade, providing suction up to 270 mmHg. The significant difference between the S1 and S2 models is the portability. This review is specifically about the S2 model, but much of it can still apply to the S1 model. 

The Spectra S2 pump is a lightweight and quiet hospital grade breast pump. Simply designed with easy to use buttons, this breast pump is a great choice whether you are exclusively pumping or doing a combination of breast and bottle feeding. There is a nightlight feature to illuminate the LCD screen and controls for those middle of the night pump sessions. Depending on what you need at the time, this pump can be used for either single or double pumping by easily attaching a tube to the front of the pump. You are able to adjust the suction, as well as the mode you are looking for, like massage or expression. The variety of settings allows you to find the perfect combination to make the most of your pumping sessions. 

This model of the Spectra pump requires a 12V adapter/charger and must be connected to a power source in order to work properly. Most easily, this pump can be plugged into a wall outlet, however you can purchase a separate portable charger or car charger, if you would like to use the pump on the go.