Mountain Buggy Duet Car Seat Adapters Clip 28 for Maxi Cosi, Cybex Aton, Phil and Teds Alpha, Mountain Buggy Protect Car Seats - New! Cybex Aton. Maxi-Cosi Cabriofix, Maxi Cosi AP, Maxicosi Pebble. This car seat adaptor will allow you to attach the following car seats to your duet double stroller (including pre 2014, 2014+ and 2017+.).