I love the little detachable mat -- it makes it so easy to pump anywhere and know that I've got a clean space to prep. The bag easily fits my two Spectra flanges with bottles plus a little ice pack (note: the bag is not insulated - I just like packing an ice pack with my flanges to keep them a little cooler). The zip pouch on the outside easily holds a small washcloth and my Pumpease as well so I always know where everything is!
I ordered this to match my Lizzy bag in Deco and it's great. I love the staging mat that comes as an easy, reusable attachment. I also love the fact the it folds up small when not in use. At work, I put my parts in here and put the into the fridge and that has been great.