这个我们家没用也。刚刚了一下Bing了一下,这个versa-tether似乎对front facing比
较有用。
Tether straps are optional. All carseats must pass minimum standards without
a tether. Tethers do improve frontal crash performance of front-facing
carseats significantly. With a tether, carseats meet a more stringent
requirement. Rear-facing tethers are also optional, but are a great feature
for added safety. Obviously, if you're in a hurry, you could simply store
the tether in the attached pouch on the back of your Roundabout. You should
use the tether whenever possible, as it does add to the safety of your
installation.