So I foster dogs, and that includes bottle fed newborns, so I often have 3 or 4 puppies to feed at a time. Afterwards, the bottles are coated with the weird, slick, oily residue of puppy formula. This kit comes with *nearly* everything you need to clean the bottles on the go.The bottles brush is just the right size for my 4 oz bottles, the nipple brush fits.both the nipples and the anti-colic insert. Having a spare soap dispenser is great too.Only complaint is the wire brush. It is for cleaning the nipple hole, but I wish it had a slightly larger brush for the other parts that sometimes need scrubbing.I have some of the right size and I just drop them in, but since they don't have a dedicated place, and they are so short, fishing them out again is a little problematic.The inner organizer piece easily twists off, so it is easy to clean, and the lid doubles as a drying rack.I've been using it for 2 weeks now and it has a permanent place in my puppy bag.