This video shows how to remove a forward-facing Clek Foonf that is installed with rigid LATCH + seat belt + tether.

The Clek Foonf is the only foward-facing car seat in the US where you use both the lower anchors AND seat belt at the same time (for kids over 35 pounds) - with all other seats it is an either or. The reason for adding the seat belt - in addition to the rigid LATCH + tether - is that there are weight limits to the lower anchors in the vehicle and adding the seat belt allows you to get the safety benefit from the rigid LATCH while ensuring that should the lower anchors not be strong enough the seat belt will be strong enough to hold the seat in the crash.

The tether strap should be used on every forward-facing car seat at all times.