Looking to turn one of the hottest strollers on the market into a super cool double stroller? Then add on the Baby Jogger City Select Second Seat Kit!. The City Select Second Seat Kit converts the Baby Jogger City Select single stroller into a double stroller. This kit comes complete with the second seat and the second seat mounting brackets.The Second Seat Kit is compatible with the City Select Bassinet Kit. It does the trick in a snap.