Peg Perego City Loop Chasis Frame and Seat True BlackTravel System Compatible The City Loop frame and any of our Primo Viaggio 4 35 infant car seats combine to create an attractive and highly functional travel system. Already have a car seat? The City Loop is also compatible with many competitor car seats with the purchase of an adapter. Minimal Footprint The City Loop chassis is compact and when combined with our Primo Viaggio infant car seats, it makes the perfect modular travel system. Front Wheels