Materials: The outer material is PUL with a liner of microfleece. The Duo Diaper comes with 2 inserts. The top insert is microfiber terry and there is a hemp (2 layers if I recall correctly) insert that snaps on to the microfiber. This diaper comes in aplix and snap closure with a snap down rise adjustment.
Fit: The Duo Diaper comes in two sizes: Size 1 fits most babies 6-18 lbs. (0-9 months), Size 2 fits most babies 18-40 lbs. (9-36 months).
How it works: The Thirsties Duo Diaper is a two size system (Size 1 for younger babies, and size 2 for older babies to potty training) with "one size" adjustments on each size to help your baby grow with the diaper. The inserts are placed in the pockets. However, the Thirsties Duo Diaper has a pocket opening at the back and the front so that the inserts can agitate out on their own in the wash. The front and back pocket openings have elastic on them. The leg openings have double gussets to help catch any runny poos.
Thoughts from Amanda:
Aesthetics - The Thirsties Duo Diaper comes in 8 bright colors (although one is pure white) and 4 prints. I liked that the colors were bold and beautiful and that there is the option of prints, even if they are very limited. I also like that the binding on this diaper on white (a Thirsties signature) which ties in the Aplix and snaps which are also all white.
Functionality - There are a couple of areas to address here. The biggest one for me is the fit. Thirsties has tackled the "One Size" issue by creating a system that involves two sizes. The Size 1 diaper is meant for "newborns" to 18 lbs. I did not use a size 1, but I have heard many people say that the diaper didn't quite make it to 18 lbs. on their child. I find that this depends on the build of your child. So, take that with a grain of salt. I used a Size 2 on my son starting at around 19 - 20 lbs. I found the diaper to be VERY bulky around his waist. This diaper is supposed to make it to 40 lbs. so I guess that's understandable, and my son is tall and skinny, but I felt as though he was drowning in this diaper whenever I put it on him. I also find that most parents (or maybe this is just me) who are interested in a "One Size" system don't want to have to purchase 2 different sizes. That's the whole point of a OS system, isn't it?
I do love that the Duo Diaper has double leg gussets. If you have a baby who will fit in the size ones and has yet to start solid foods this may be a great diaper for you. No need to worry about those runny poos leaking out of the legs here. I also enjoyed that the inserts were microfiber terry and hemp! Not many diaper companies offer that feature as a standard. The inserts snap together at the front and the back of the insert making sure there isn't any slipping or sliding which was lovely. Also having a pocket opening at the front and back of the diaper so the inserts could agitate out is handy (think Smartipants). I did find that the inserts took longer to dry when snapped together though, so I always took mine out by hand and unsnapped them.
A tip - When putting in your inserts make sure to place the PUL flap at the front of the diaper over the top of the insert. This will prevent leaks out of the top of the diaper. Especially compression leakage if you intend to use this diaper as an overnight solution for a tummy sleeper.
I am giving the Duo Diaper a 4 because although the features themselves are great and worth the money, I just don't love a system that requires me to buy 2 different sizes of diapers. I am a true "OS" girl at heart. :)
Durability - The Duo Diaper held up fabulously to many washings. The hemp insert was fully absorbent at about 8-10 washes I'd say. My diaper was aplix as Thirsties had yet to come out with a snap version, and I found the Aplix to be very soft yet wonderfully sticky as well. Usually that area seems to be a trade off. I did wish that the tabs were a little bit longer but, they worked well.
**** I did purchase Thirsties Duo Wraps for my daughter to use as a newborn so I will let you all know how I feel about those (same idea - 2 size system, only covers) when I get to use them.