The top tether is a strap that when anchored prevents the top of a car seat from moving forward in a crash.
The top tether is found on the top back of your car seat and looks like a long strap with a hook at the bottom. The anchor location varies from car to car so it is best to check your owner’s manual to find out where your anchor can be found.
If your vehicle does not have an anchor, it is very important that the tether be rolled tightly and secured with a tight rubber band to prevent it flying forward and causing facial injury in the event of a crash. Tether anchors can also be installed in older model vehicles. Some dealers even offer free tether anchor installation services in older cars.