Twin Stroller Connector for Baby Universal Fits Umbrella Strollers Babyzen YOYO Yoya Etc.. Turns Two Single Strollers into a Double Stroller : Amazon.com.au: Baby
Babyzen YoYo² Twin Setup with Connectors (Side by Side) - TinyExplorers
YOYO Bassinet Stroller Adapter | BABYZEN™ YOYO Connect with Bassinet