Question: what is the difference between the spectra 1 and 2?
Answer: With either Spectra S1 and S2, you can control the the suction strength and cycle speed independently. The MAIN DIFFERENCE is just Spectra S1 has a built-in battery that lasts for 3 hours (if fully charged) while Spectra S2 does not. As a result of this: Spectra s1 is much more portable than Spectra S2.