Bought this as going on a coach trip holiday, therefore would not have a microwave available.
Also, as I have a toddler as well as baby in a pram, did not really have the capacity to carry my full size steam steriliser.
This is ideal - it packs away inside itself - kind of like stacky cups. You simply stack it up, pour in the correct amount of water (measuring jug included which fits inside the compacted steriliser), load it up and set it away.
I have wide neck bottles (Pur Simplicity) which have quite a large bottom and could fit two of these, plus lids, teats, rings and two dummies without problem.
This is definitely my best baby related purchase ever (and believe me I've made a lot!! :-D)
Ideal for non self catering holidays (e.g. hotels) etc especially if you don't have your own transport to the place