What is a tether and when is it used?
A tether is a webbing strap that is attached to the top of a safety seat on one end (see Top tether) and equipped with a hook or other fastener on the other. When the safety seat is forward-facing, the tether is attached to a designated vehicle tether anchor (see Top tether anchorage). Attaching a tether can reduce the forward motion of a childs head in a crash by 4, 6, 8, or more inches, depending on the size of the child and the severity of the crash. Use of a tether for forward-facing safety seats is strongly recommended. Tethering a rear-facing safety seat is less common and is only allowed on a few models (see Top tether, rear-facing). A tether is not necessary on booster seats, but some manufacturers suggest leaving it attached even after the harness on a combination seat has been removed.