Other car seats can work with this stroller with use of an adapter. (mommystroller.com)
The first is to make use of the adapters included in the box. (androidheadlines.com)
Takes two travel systems or two single mountain buggy carrycots; Compatible with Graco Snugride and Peg Perego Primo Viaggio car seats with use of adapter (sold separately); (smartbabyhq.com)