The Spectra 12 Volt Power Adapter is compatible with only the S1, S2, S3, and SG Breast Pump models with a manufacturing date between 02/2015 - present. The Spectra 12 Volt Power Adapter has an output of 12 Volts/2 Amps to properly power a sustain the electrical current of the compatible breast pump motor. The Spectra S1, S2, S3, and SG Breast Pump models are international voltage compatible at 100-240 Volts and 50/60Hz, which will allow the Spectra 12 Volt Power Adapter to only need a prong converter for the country being used in. Included is 1 Spectra 12 Volt Power Adapter and 1 detachable US outlet prong.