The Second seat kit will allow you to transform the baby jogger city select stroller into a double stroller without having a wide double stroller.
45 Lb Weight Capacity.
Great Way to add a Second Child to Stroller without having a wide double stroller.
Please note: You can use your stroller for a single child in the upper position but, if you decide to use it for a second child (twins or two close in age) in the lower position you must purchase the second seat. The second seat comes with the mounting bracket needed to convert your stroller from a single to a double.