The economical Essential Delux Citi is perfect for a family who wishes to move quickly with the twins. The quick click and go Streety bases install with a car seat belt. The Maxi-Cosi Citi will install onto this base swiftly. This 3 in 1 travel system will include the Maxi-Cosi Citi car seats and bases as well as the Double Trouble Twin pram. All the items will install onto the frame quickly and easily.