"Letdown mode" refers to feeling disappointed, upset, or dissatisfied when our expectations are not met. It describes the state of being let down or disappointed with a situation or person. Full definition
Unlike other electric pumps, you can adjust the suction level in letdown mode or regular expression mode. (thespruce.com)
This is a common misunderstanding because a lot of breast pump brands will automatically start in massage mode, and then swap to letdown mode after a few minutes. (pumpables.co)
The Spectra S2 Plus Electric Breast Pump features an adjustable letdown mode, hygienic closed system, nightlight and timer. (babycenter.com)