This is a large unit that takes up a good amount of counter space. It includes six bottle sterilization necks where the hot air / liquid flows up to sterilize the bottles. That means this product can only sterilize 6 bottles max per run. It runs for 60 minutes. I think it is a little confusing for them to say it can store 12 bottles. You can use at as storage with the unit turned OFF and it can physically fit 12 bottles that way. But it only has the physical capacity to sterilize 6 bottles per 60-minute cleaning session.It has three layers. The first layer is where you put the water (under the bottles). The second layer is for the bottles. And the third layer up top is for the lids and caps.We have four children including an infant and my wife pumps a lot of breastmilk. This is really convenient to have considering the number of bottles we go through in a day. I wish we got something like this years ago. It works mostly as expected. Note that the layers can only be assembled in 1 direction, they are ever so slightly different in the back, so if the lid is reversed it almost fits but not quite so it is a little confusing putting the lid or third layer back on. This would be a lot better if it those parts were just reversible as it’s hard to tell by looking at the lid or third layer which was is front. Then second layer has the logo so you can always see which way is front. We move them to a bottle drying rack after running the machine.In summary, works fine, smaller capacity than advertised, takes up a lot of counter space, but really useful.