As I just explained, due to the LockSure system, this car seat can be installed without the base. It's very easy to pull the seatbelt through the belt path and firmly secure everything. Look at it and notice that there's a belt path in the front and also a belt path in the back to help you achieve even more stability and a higher level of safety, even when you're installing the seat without the base. This is very convenient when you're driving with taxis, or you switch between your car and the stroller a lot.