I am 2 mths postpartum and own a haenim UV sterilizer as well. Prior to delivery, I just put the 4 milk bottles and the pump parts of my Spectra S1+ in the sterilizer after washing. All ready to be sterilised when baby is discharged since it only takes 30min. You shld be able to fit all tht I have mentioned into your machine as well since there are 2 levels once u insert the rack. In fact, subsequently, I even bought another 2 bottles. And they still fit.