The Stokke® Xplory® car seat adaptors are compatible with Xplory® strollers with serial numbers 24771 and up. Earlier models cannot be upgraded to fit the car seat adapters. Our own Stokke® iZi Sleep™ by BeSafe® car seat, which was launched in 2010 and which is especially adapted to be mounted directly on the chassis of the Stokke® Xplory® stroller without the need for adapters, can be used on any Stokke® Xplory® chassis, regardless of the model or year of production. For more information on the Stokke® iZi Sleep™ car seat, please follow the link below: http://www.stokke.com/global/car-seats/stokke-izi-sleep/3810.html