I ordered it to connect between Citi mini stroller and Cybex car seat and it is fit perfectly!Very easy to assemble.
The adapter works but sometimes it's a little challenging to line up the car seat perfect and get it to snap in and then when you're ready to remove it sometimes it gets stuck and you have to use some force to pull it off which isn't always great when you have a sleeping newborn in the seat.
HOWEVER...when I put the car seat onto it, there was no click and it would not sit all the way into the adapter.
If you are having trouble getting it to click in make sure you install it on the lower of the two holes on the sides of the stroller.
It was a gamble but it paid off after several frustrating attempts to get the adapter to FIT properly into my new City Mini GT (2017-2018 model) The problem is the adapter does not come with instructions - just a photo on the box.
What is in the picture is not what you get, had to purchase many times to figure this out, to Amazon's expense.
I'm so disappointed in this stroller/adapter system - it's expensive and advertised to work great with twins in car seats, but it doesn't seem to work at all.
Doesn't work for City Mini GT - I bought this for my City Mini GT and apparently it doesn't work for it.
I have a Chicco Keyfit 30 car seat and a Baby Jogger City Mini.
After it was all said and done, and I put the stroller to the test, the car seat did indeed fit in the stroller.